February 2010 Archives

Walt Kelly (1913-1973), creator of the comic strip Pogo, once remarked, "What's good about March? Well, for one thing, it keeps February and April apart."

Kelly understood that March, more than any other month, can manifest the temperature characteristics of both winter and summer. This year, Chicago's March is off to a decidedly wintry start, but big changes are on the way. Daytime highs, six degrees below normal today, will climb to a rainy eight degrees above normal by Sunday.

Meteorological spring begins today

Today marks the start of meteorological spring, the three-month period from March 1 through May 31.

For meteorologists, a season is considered to be a division of the year according to some regularly recurrent weather phenomena. In the mid-latitudes, seasons are based upon the annual cycle of heat and cold; in the tropics (which lack significant temperature fluctuations through the year), seasons are often described in terms of the annual cycle of rain.

-- Richard Koeneman, WGN-TV Meteorologist

Dear Tom,
The humidity is often very high in the winter here in Chicago, yet we always hear how dry the air is and that it is desirable to add moisture to the air in our houses. Can you explain this contradiction?
-- Billy Kleiman

Dear Billy,
Averaged through the year, Chicago's relative humidity is 71 percent but, surprisingly, it runs a little higher during the winter (73 percent) than during the summer (68 percent).
The explanation for higher winter humidity levels is that very cold air contains minimal moisture, even when saturated (100 percent relative humidity). It therefore takes little moisture to elevate the humidity of frigid air. Far more moisture is required to bring hot air to saturation. It takes only 0.001 ounce of water to saturate one cubic foot of air at 0 degrees, but 0.022 ounce (22 times as much) to saturate air at 80 degrees.

Yesterday's Tsunami took mariners by surprise in Huatulco, Mexico.  For more on this and a listing of Tsunami wave reports from across the Pacific Ocean, follow the link below to the  WGN Severe Weather Blog

http://weblogs.wgntv.com/chicago-weather/severe-weather/

February 2010 will soon be history, and if measurable snow does not fall Sunday this month will go into the record books, tied with February, 1967  for the fourth snowiest on record, with a total snowfall of 22.5 inches. In addition to the heavy snow, the month featured virtually no warmth---only one day broke 40 degrees. Since the start of the year, Chicago has recorded only  four days in the 40s, and the highest temperature so far in 2010 has been only 46 degrees. The chilly trend will continue through March's opening days but signs of a modest warm-up are visible by the end of the week as readings are expected to climb into the 40. The next storm is likely to bring rain instead of snow.
 
Cold, snowy February suppresses severe weather

One positive aspect to this nation's cold and snowy February has been a nearly total lack of severe weather. With only one day left in February, not a single tornado has been reported in a month that has averaged 37 twisters since 2000.
 

 

Dear Tom,
Has snow ever covered the ground for the entire December-February meteorological winter period?
---William Ooms Jr., Alsip, and Greg Wolf, Barrington Hills
Dear William and Greg,
Snow cover has been quite persistent in the Chicago area since the first snowfall on Dec. 7-8, but it has not been continuous. Phil Rider, the Mundelein observer, reports 74 days with 1 inch or more of snow cover through the end of February but noted that during January's last week just traces of snow remained. Midway Airport observer Frank Wachowski logged 66 days with similar periods of bare ground. In a typical Chicago winter there is 1 inch or more of snow cover on 43 days, so this season is well above average. Only once has Chicago been snow covered the entire winter: in 1978-79 with a record 100 days of continuous snow cover from Nov. 26 to March 5.

A massive and still powerful storm has dropped over 50" of snow on portions of the Northeastern United States.  This same storm brought Chicago a little snow overnight.  For the very latest on the storm follow the link below to the WGN Severe Weather Blog

http://weblogs.wgntv.com/chicago-weather/severe-weather/

It's a first for New Yorkers. Nothing like the parade of megasnows which have lambasted the Big Apple in February has happened before. The latest storm, one of three which have hit the region in just the past month, roared into the city late Wednesday on 30 to 40 mph winds and generated 33 hours of uninterrupted, often heavy snowfall. When the snow finally broke late Friday, New York had been smothered by 21 inches of snow while just across the Hudson River in New Brunswick, N.J., the tally hit an astounding 37 inches. Sparta in northwest New Jersey came in a close second recording 33" of snow. To the northwest in the Catskill Mountain community of Woodridge in southeast New York, an off-the-charts 46.9" of snow had occurred. In effect, more than a season's worth of snow had fallen with a single storm over a day and a half's time. New York City's Central Park February tally of 37" made it the city's single snowiest month ever. The total eclipsed the previous single-month record of 30.5" set in March 1896. Snow records in New York City extend back to 1869.

Storm winds hit 90 mph on New England Coast; 125 mph on New Hampshire's Mt. Washington

Friday's storm was devastating across sections of the mid-Atlantic and Northeast. Nearly a million homes and businesses in a multi-state region extending from New Jersey and Pennsylvania north across New England were without electricity, including 40% of the homes in New Hampshire alone. The huge storm slowed to a crawl Wednesday and Thursday as it became ensnared in an atmospheric blocking pattern. The "block" was produced by a pool of mild air to the north, which generated a stubborn high pressure system which impeded its forward motion. The system was forced to spin in place, sweeping vast quantities of moisture into the region. In the hardest-hit locations of coastal New England, that led to 8" of wind-driven rain which arrived on gusts as high as 90 mph at Portsmouth, N.H. Mt. Washington clocked 125 mph winds. As the moist air swept westward into cold air, gargantuan 3 to 4 foot snows resulted.

Long cloudy spell to accompany Chicago's February to March transition

The storm's circulation transported snow westward into Ohio, Michigan and Indiana late Friday where 1 to 4 accumulations were reported. The westbound snow reached Chicago late Friday evening. A dusting to a half inch was expected Friday night into Saturday morning. The Atlantic moisture driving the snowfall is to hold here into next week and promises to shroud the final weekend of February in clouds with spits of snow and pockets of milder air aloft contributing to the chance of patchy drizzle.

The book on February 2010's weather closes at midnight Sunday night. The month managed a peak temperature no higher than 42 degrees -- making it the first February in 31 years unable to produce a maximum reading that low. By comparison, a 61-degree high was logged last February.

Check out pictures from the storm in this blog posting.

-- WGN-TV Weather Center

Dear Tom,
I remember walking to school in March 1970 in one of the heaviest, wettest snows I've ever experienced. Can you help with the details?
--Zoila Berling, Bakersfield, Calif.

Dear Zoila,
Our recent encounter with heavy, wet snow was tame compared to the crippling storm that hit the city March 25-26, 1970. The official snowfall at Midway Airport was 14.3 inches, with a water equivalent of 1.76 inches, making the snow-to-water ratio a sopping 8-1. The storm was accompanied by thunder and lightning and fierce northeast winds that piled the snow into 3- and 4-foot drifts. The snow was so heavy it caused considerable damage to trees, shrubs and power lines. Vehicles could not navigate the snow-clogged streets and hundreds of cars stalled or were abandoned. With the visibility near zero, the city's airports were forced to shut down, stranding thousands of passengers.

 As  high-level cloudiness rolled into the Chicago area as wrap-around moisture from the monster storm in the Northeast sun dogs were visible in the Chicago area. Thanks to Chris Alexander for passing along these pictures taken in the Oak Lawn-Hometown area around 8:30 a.m. this morning.

 

Photos by Chris Alexander

Thanks to our frequent blog contributor Mark Vogan who passed along this shots of a snowbound Scotland. The photos were taken after a 36 hour period of heavy windblown snow. Winds of gale force piled the snow into drifts 2-5 feet high and even up to 10 feet in some areas.

Mark notes that while some areas got as much as 14 inches, areas as close as 15 minutes away got no snow at all with an elevation difference of less than 1,000 feet. Many areas in Scotland above 1500 feet have received as much as 2 feet of snow from this storm with severe blowing and drifting.

  

Photos by Mark Vogan

More shots of snow-covered New York City taken in and above Times Square.

 

Photos by Keith Danish

 

 

Thanks to Lindsey Lullo for passing along these photos of the eastern snowstorm that has brought at least a foot to the Stroudsburg area in eastern Pennsylvania.

Photos by Lindsey Lullo

New York City is in the midst of a major snowstorm that had dropped 21 inches of snow on the city through late Friday afternoon. Thanks to Keith Danish for passing along this photo taken near 7th Avenue and 15th Street.

Photo by Keith Danish

Another shot in the same location taken several hours later

Photo by Nat Rahav

The weather's at it again. In a winter which has taken all sorts of unusual meteorological twists and turns, Friday's sunshine in Chicago appears likely to fall victim to incoming clouds by late in the day. But rather than arriving from the west, Friday afternoon and evening's cloudiness is to sweep in from the northeast. Once here, these clouds are to dominate the coming weekend---the final weekend of meteorological winter---producing periods of light snow Friday night into Saturday. The westward-drifting cloud shield is being generated by the latest mammoth winter storm to hammer the Mid-Atlantic and Northeast.

In New York City, a rain/wet snow mix Thursday morning had transitioned to heavy, wet snow by afternoon. A half foot of water-logged snow had accumulated by late in the day downing some trees along famed 5th Avenue. A falling limb there, snapped by the weight of the snow, fatally injured a pedestrian.  New York City's snow was far from over as nightfall arrived. Crippling snowfall is predicted to continue in the Big Apple at least into Saturday morning with accumulations expected to exceed a foot. Visibilities in Central Park late Thursday evening had been slashed by  heavy snowfall and howling 30 to 40 mph wind gusts to a quarter-mile.

Farther north, drenching coastal rains riding 40+ mph gusts north of the storm's center along the New England Coast were relentless Thursday. Rain totals in eastern Maine had topped 5 inches by day's end---and rain continued to fall heavily. Once inland, the region's mountains---including Eastern Pennsylvania's Poconos, the Catskills and Adirondacks of Upstate New York and the White and Green Mountains of Vermont and New Hampshire---poked up into the inland-rushing flood of Atlantic moisture changing it to snow. Snow totals there were eye-catching. West Halifax Vermont reported 38.5 inches, Altamont New York 30.5 inches while Kancamagus New Hampshire had 26.0 on the ground---and snow was still falling.

Forward movement of the storm came to a halt Thursday as a blocking pattern developed to its north. Though the system begins weakening slowly Friday, powerful easterly winds on its north side are predicted to force moisture and clouds westward toward the Midwest. The increase in cloudiness predicted in Chicago Friday afternoon and evening, as well as the threat of light snow expected to arrive Friday night are both by-products of the storm and its slow movement.
 
Chicago in the midst of it 7th snowiest season, February comes in #3 of the past 125 years
 
Wednesday evening's thundery Chicago area snowburst ended up producing  3.6 inches at O'Hare, enough to push February's tally to 22.4 inches---the third heaviest in 125 years of official snow measurements--- and the seasonal total to 52.3 inches---the 7th heaviest on record since the 1884-85 snow season.
 
Thursday becomes the first 100 percent sunny day here of the past 44
 
Sunshine was uninterrupted Thursday. It's the first day in 44 that the city has been treated to 100 percent of its possible sunshine. Only 36 percent of the month's possible sun has occurred in February---below the 46 percent level considered typical this month.
 

Dear Tom,
My daughter was born Feb. 20, 1976. I remember bringing her home and sitting on the front porch with her and I believe the temperatures were near 70 degrees for about a week.
-- Ostego

Dear Ostego,
Chicago logged a temperature of 58 degrees on the day of your daughter's birth, but the next three days were chilly (highs of 43 degrees, 34 and 40). However, a strong warm-up began Feb. 24 and carried through the end of the month, and that's the period you remember. Chicago's daytime temperatures averaged 22 degrees above normal from Feb. 24 through Feb. 29 (1976 was a leap year). Chicago's normal high during the last several days of February is about 40 degrees.
The city's official thermometer registered 75 degrees on Feb. 27, a record high for the date, and we can't imagine a more ideal day for sitting on the porch with a new daughter.

 Ron Sieniawski from Mt Prospect sent us this picture of the snow taken with his iPhone in Arlington Heights Wednesday evening.

Thanks for the great shot Ron!

Last night's storm dropped snow with the intensity of the "Blizzard of Short Duration" that struck Chicago almost 43 years to the date on February 23, 1967. That storm had much stronger winds and was not a result of lake effect. However, it dropped the visibliity to near zero, deposited similar amounts of snow, crippled traffic and was also accompanied by thunder and lightning.

It's official.  The 3.6" of snow at O'Hare yesterday pushed our seasonal snowfall so far to 52.3".  That is almost double what we normally have at this point in the winter.  Even more significant, this marks the third straight winter with snowfall of 50" or more. 

The last and only other time on record this occured was back in the 70s.  At the end of that three year streak was the record winter snowfall of 89.7" during the winter of 1978-1979.  That winter also had a political storm that swept through the heart of the "Chicago Machine".  Winter weary voters vented their frustration at the voting polls.  Baby boomers like me will recall those nasty winters of the 60s and 70s. 

For more fun pictures of winter in Chicago, click here for a Chicago Tribune gallery.

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Intense lake-effect snows hit sections of the Chicago metro area hard and fast Wednesday evening with whiteout conditions embedded with flashes of lightning and crashes of thunder, which continued sporadically over several hours. Thunder and lightning occur as air rushes aloft. This upwelling encourages air to sweep into the system concentrating moisture which leads to especially vigorous snowfall.

From Kenosha to Waukegan, Gurnee, Skokie, Mt. Prospect, Oak Brook and Batavia south to Bolingbrook, Ottawa, Joliet and Palos Heights---and, across the city of Chicago---snow fell furiously and accumulated in a matter of just hours to as much as 6 to 8 inches. Late evening traffic slowed to 10 mph on the snow-covered Kennedy Expressway (I-90) and the Reagan Memorial Tollway (I-88). Preliminary totals by late Wednesday evening, with snow still falling at some locations, had reached nearly 8 inches at Gurnee and near Golf and Busse Roads in Mt. Prospect, 6.2 at Beach Park, 6.0 at Zion, 4.3 at Oak Brook and 4.0 at Bolingbrook, Des Plaines and Northbrook.

An inch of snow had fallen at O'Hare by 8:30 p.m. Wednesday, with snow still coming down hard. That was enough to push the city's official seasonal snow tally above 50 inches for the third consecutive year. There's been only one other string of three consecutive 50+ inch  seasons in 125 years of snow measurements here and it occurred between 1976 to 1979.

Lake effect snows occur in especially cold environments which, because of the efficiency of ice crystal formation at low temperatures, frequently produce larger than typical accumulations from the limited amount of water vapor available. This leads to snowflakes which exhibit maximum "fluff". Estimates of Wednesday's snow puts snow/water ratios at 30 to 1---indicating the system's snowflakes had almost three times the volume of those which come down in more typical 10 to 1 ratio snow events. One witness, in describing the rate of snowfall in Evanston, compared the scene to a "snow globe."  Another described "pure whiteout conditions with snow coming in horizontally" and still another characterized the snowfall intensity at its height Wednesday evening as "this season's heaviest."

A "meso-low" over Lake Michigan--a compact area of low pressure which, when enriched with lake moisture is capable of producing intense bursts of snowfall like those observed here Wednesday evening---first appeared east of Door County Tuesday evening. The system proceeded south the length of the lake Wednesday sending bursts of heavy snow into the Milwaukee area in the afternoon resulting in local 4 to 4.5-inch totals.
  

Northeast braces for hurricane-intensity winter storm
 
Barometric pressures over the western Atlantic east of Florida Wednesday were in free-fall. A developing      northbound storm system was predicted to intensify explosively before reaching the mid-Atlantic Coast near New York late Thursday and stalling. The storm was behind the maze of weather watches and advisories which had been issued late Wednesday spanning sections of 34 states. New York City, with 30.5 inches of snow on the books this season (17.9 is normal) and Philadelphia with 73.1 (13.8 inches is normal by this date) are among the areas threatened with significant accumulations after a switch from heavy rain to snow. Mountainous areas from Pennsylvania across Upstate New York and New England, may measure snow in feet before this storm finally departs. And powerful east winds on its north side are likely to send clouds and light snow westward as far as eastern Illinois and Wisconsin by the weekend.
 
     


 

Dear Tom,
The narrator in a Discovery Channel special said thunderstorms sometimes occur over the Arctic Ocean even though it is mostly ice-covered. Do they have their facts straight?
--Donna Peklo

Dear Donna,
Thunderstorms do occur in the frigid north polar region, though rarely.
Barrow, Alaska, on the shore of the Arctic Ocean at 71 degrees north latitude, is North America's northernmost habitation and, in weather records dating from 1910, observed its first thunderstorm June 20, 2000. Thunderstorms had been seen there before, but always at a distance and never in the town itself.
An essential ingredient of a thunderstorm is a current of rising mild air in which water vapor is condensing into precipitation particles that generate electric charges sufficient to trigger lightning. A dearth of mild air in the Arctic greatly limits thunderstorm activity.

Thanks to Patrick  Korellis for this shot of tonight's heavy snow in Gurnee. Patrick, a past WGN Weather Center intern, reported the snow was so heavy that he could barely see in front of him.

Photo by Patrick Korellis

Thanks to Matt Piechota who sent this picture taken near Naperville and Butterfield roads about 8:10 p.m. this evening. The snow was falling at the rate of two inches an hour.

Photo by Matt Piechota

Thanks to Steve Newlin of Gurnee for passing along this photo taken during the height of tonight's snowstorm. The area received upwards of 6 inches of snow.

 

Photo by Steve Newlin

Thanks to David Lastrucci of Mt. Prospect for sending along this photo of the heavy snow that brought anyhwere from 3 to  as much as 8 inches to much of the north and east portions of the Chicago Metropolitan area,

Photo by David Lastrucci

Thanks to David Lastrucci of Mt. Prospect for sending along this photo of the heavy snow that brought anyhwere from 3 to  as much as 8 inches to much of the north and east portions of the Chicago Metropolitan area,

Photo by David Lastrucci

Sections of Cook County (including the City of Chicago) could see up to 5" of snow tonight.  For the latest, follow the link below to the WGN Severe Weather Blog

http://weblogs.wgntv.com/chicago-weather/severe-weather/

Lake-effect snow doesn't happen every day in Chicago. But, when the atmosphere produces a perfect amalgam of small and large scale atmospheric features,the lake snow machine is set in motion. The manner in which snow falls and accumulates in such situations is both fascinating and tricky to predict. Unlike the snowfall attending larger storm systems, which often falls over large areas and with fairly predictable variations in accumulation, the amount of lake snow which piles up in any one location is often influenced by comparatively tiny shifts in wind direction, the length of time over which snow falls, and the intensity with which it comes down, all of which can be modulated by small-scale terrain features like hills or moraines. These can change the amount of "lift" which takes place and that affects precipitation intensity. Areas of increased "lift" maximize precipitation, just as mountains do out West.

That perfect combination of atmospheric appears to be coming together Wednesday and Wednesday night in the counties adjoining Lake Michigan's west and south shores. Northwest Indiana's snow belt may well end up at the epicenter of the developing lake snow episode. If all unfolds as predicted, the hardest hit locations in sections of Lake, Porter and La Porte Counties, as well as in Berrien County Michigan, could be in for 8 to 12 inches of snow---or more. But lake snows are also predicted to sweep onshore in sections of  northeast Illinois and eastern Wisconsin. Parts of Cook and Lake County Illinois may be in for 2 to 5 inches snowfalls if early indicators hold together.

A late season blast of cold arctic air, which sent readings tumbling as low as 10-below late Tuesday across sections of the Dakotas and Minnesota, sets the stage for this area's lake snow. Jet streams strengthen as colder air arrives. The  "lift" which cools air to saturation and aids in snow development, is especially vigorous beneath the leading edge or strong pockets of jet stream winds known as "jet streaks". When further enhanced as cold air flows over warmer lake waters, the prospects for lake snow take off.

The process was clearly getting underway Tuesday evening as evidenced by falling barometric pressures and the development of a wind circulation east of Door County, Wisconsin. A feature referred to by meteorologists as a "meso-low"---"meso" referring to a medium-sized disturbance, as versus a "macro" or large scale system, was under development and expected to head south over Lake Michigan into Wednesday. Meso-lows in winter, when over large bodies of water have access to moisture that can set bursts of especially heavy snowfall into motion. As this disturbance settles closer to Chicago Wednesday afternoon and evening, the potential for the snowfall to grow heavier and more frequent in lakeside locations may well be enhanced. Just how intense how any resulting snow bursts become will influence accumulation.
 
 
Texas hit by snow again; same system could bring eastern U.S. mountains snow measured in feet
 
The same southward plunge of cold arctic air helped fuel the latest round of snow to hit Texas and the Deep South Tuesday. By evening, the heaviest snow totals in the Lone Star State included 6.0 inches  at Sweetwater, 5.3 inches Palestine, 5 inches Baird, 4.4 at Midland (a new record for the date) and 3.5 at Waco. That eastbound disturbance is to proceed off the Florida coast Wednesday where it will begin intensifying explosively. The mammoth storm which results is to continue north then stall over the Mid-Atlantic just north of New York City late in the week and into the weekend. Its slow pace of movement should keep snow piling up across the region prompting the issuance of winter storm watches from Washington D.C. to Philadelphia, Atlantic City and much of interior New York and New England. Mountainous areas there could measure snowfall in feet over coming days---while areas like New York City, where heavy rain is to fall first, are to expected to experience a switch to snow which may produce significant accumulations amid howling winds.

The mammoth system's reach could ultimately extend westward into the Midwest bringing clouds and some periods of light snow to Chicago toward the weekend. Gusty winds here in coming days will be increasingly related to the deep storm's circulation.
 
Late season arctic chill to bring Chicago its chilliest daytime temps in 10 days
 
Daytime highs in the 20s Thursday would be the coldest to occur in Chicago since a 28-degree high on Feb. 15.
 

Dear Tom,
Which of Chicago's extreme temperatures is the rarest? Highs of 100 degrees or higher, subzero highs, lows in the 80s or lows of minus 20 or lower?
Kevin Dowling, Westmont

Dear Kevin,
Your question indicates how varied a climate Chicago has. Aided by Chicago climatologist Frank Wachowski, we tallied Chicago's extreme temperatures since late 1870. The most frequently occurring extreme was days with triple-digit heat with 61 on the books. Subzero highs were next with 45 days followed by 28 overnight lows of 80 degrees or higher. That made the 15 recorded low temperatures of at least 20 below the city's rarest extreme. All four temperature extremes have been logged fairly recently. The city's last 100 was in July 2005, the last subzero high in January 2009, the last low in the 80s in August 2006 and the last minus 20 day in January 1994.

Even with the clock ticking on February and three month December through February meteorological winter season, Chicago's 2009-10 snow tallies are already among the heaviest on record.  And the area's weather history is clear: the snow's not over yet.  About a quarter (24 percent) of Chicago's snow takes place beyond this date.

The sporadic flurries, expected to flutter earthward at times in coming days, could become more formidable Wednesday afternoon and night if, as expected, some lake moisture becomes involved. North winds channeling cold late-season arctic air the length of  Lake Michigan into Chicago raise the possibility of at least some accumulation Wednesday afternoon and night, particularly lakeside counties. 

If true, that's likely to push already impressive Chicago snow numbers even higher. The 18.8 inches of snow on the books through late Monday has created a three-way tie for the 5th snowiest February to-date in 125 years. And the city's seasonal snow total of 48.7 inches ranks 8th snowiest since 1884-85. That's nearly 20 inches higher than the long term average to date and just 1.3 inches short of becoming the third consecutive 50-inch+ season.
 
Warm temps and weekend disturbances' rapid movement behind less snow than predicted
 
Predictions of snowfall in Chicago's late weekend storm ended up too high. Mild temperatures impacted the snowflake formation process at cloud level Sunday night shrinking their size. The snow which fell possessed half the volume expected. Measurements of its snow-to-water ratio averaged 6 to 1---i.e. 6 inches of snow for every inch of water---half the typical 12 to 1 ratio. That plus fewer hours of snowfall, because of the system's rapid movement, limited accumulations to 2 to 6 inches---and even less to the south toward Kankakee and Downstate.

Latest U.S. winter storm sweeping Texas
 
Winter's latest U.S. storm was following the southern route from Arizona and New Mexico into Texas late Monday.  Snows beneath that system's northern flank were predicted to reach 1 to 5 inches in the Amarillo area. Three days of snow with the system a mile south of Wolf Creek Pass in south-central Colorado buried that area beneath 45 inches.
 
 


 

Dear Tom,
Does precipitation on Lake Huron or Lake Superior raise the water level of Lake Michigan?
Ed White, Grayslake

Dear Ed,
The surfaces of Lake Michigan and Lake Huron lie at the same mean elevation, 578.7 feet above sea level; hydrostatically, they are one lake.
The levels of lakes Michigan and Huron, separated by the Straits of Mackinac, whose depth is 150 to 350 feet and five miles wide at its narrowest point, fluctuate as a unit. Consequently, major precipitation that raises the level of Lake Huron --- such as an inch of rain over the entire surface of Lake Huron --- would also raise the level of Lake Michigan.
Lake Superior, at a mean surface elevation of 600.4 feet, drains into Lake Huron via the St. Marys River. Precipitation on Lake Superior cannot directly affect the level of lakes Michigan and Huron, but outflow from Superior will increase when its level rises.

Bob Schneider, who lives on on Bluff Lake in Antioch, Illinois sent us these pictures. Bob tells us:

The one titled "Ice Fog" was taken a couple of days ago at sunrise with the fog before it burned off. The one titled "Ice Golf" was taken today after seeing a 4-wheeler plowing the snow on the ice and then people began to show up with their golf clubs. You can see the pins for the holes on both sides of the picture.

Thanks Bob!

"ICE FOG"

Noelle Bender from Aurora sent us this picture of male and female cardinals.

Thanks Noelle!


Photo courtesy of Noelle Bender, Aurora, Illinois

Bob Johnson from Buffalo Grove sent us this picture. Bob said:

"here's a street  scene for you taken  this  morning Monday  February  22"

Thanks Bob!

Larry Jahn from Macomb sent us these shots of the snow there. Larry tell us:

"We haven't seen the grass since about Christmas, with one brief exception.  As the yardstick shows, we have 10 inches on the ground, probably got about 8 inches  overnight here."

A new study published online Sunday in the journal Nature Geoscience suggest that there will be fewer but stronger hurricanes in the future.  Ten experts in the fields of climate change and hurricanes that formed a special World Meteorological Organization panel looked at computer models that forecast tropical cyclone activity through the end of this century.  The wind speed in storms is expected to increase anywhere from 2 mph to 11 mph.  That is the bad news.  The good news is that there will be between 6 and 34 percent fewer storms.

 

At the top end of the range, an increase of wind speed near 11 mph would mean in increase in damage of about 60 percent.  Those stronger storms would also produce more rain.

 

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For the very latest on this developing winter storm, follow the link below to the WGN Severe Weather Blog.

http://weblogs.wgntv.com/chicago-weather/severe-weather/

A rain-snow mixture turned into a heavy, wet snow overnight that was expected to lay a band of 4 to as much as 9 inches of snow across the region. By mid-Sunday evening up to 2 inches had fallen in areas along Interstate Highway 80 while totals in western Illinois were approaching 7 inches near Macomb.

With temperatures hovering near freezing the snow was heavy and wet in nature, making it difficult to shovel and causing tree limbs to sag under its weight. The storm was expected to send Chicago's official February snow total above 20 inches for the third time in the past four years, and bring the city its third consecutive 50-plus-inch snow season for only the second time in history.

The snow should end just after this morning's commute, setting the stage for a cold last week of February. Afternoon high temperatures should range from the upper 20s to middle 30s which would close the books on February 2010 with only one 40-degree day -- a 42-degree high on Feb. 19. The cold weather should persist as March opens with below-normal temperatures expected to cover most of the eastern half of the nation.

Dear Tom,
My parents were married May 6, 1960, and while putting together a commemorative display wanted to include a Cubs score. It turns out they didn't play at all from May 6 to 11. Was weather a factor?
-- Tom Widlowski

Dear Tom,
Weather was indeed a factor as the Cubs fell victim to six straight postponements due to a combination of rain and cold weather. Heavy rain washed out the May 6 game, and the next five games were plagued by off and on light rain, chilly temperatures and gusty winds. Temperatures from May 8 to 10 hovered near 40 degrees at Wrigley Field with brisk north winds adding to the discomfort.
After the sixth rainout manager Lou Boudreau commented that "our pitchers were so rested now, I'm afraid they'll start to rust."
The six straight rainouts were not a record: in August 1903 the Philadelphia Phillies lost nine straight games to the weather.

For the latest on the approaching winter storm including the updated winter weather warnings and advisories, follow the link below to the WGN Severe Weather Blog

http://weblogs.wgntv.com/chicago-weather/severe-weather/

Snow is expected to begin Sunday afternoon and spread north, possibly mixed with some sleet in parts of the area near and south of Interstate 80. As the center of low pressure tracks across southern Illinois into central Indiana, snow will increase during the evening hours. A little before midnight will begin the period when snow will fall the hardest in the Chicago area, perhaps as much as an inch an hour in some areas. Travel conditions will deteriorate rapidly and roads will become slick and hazardous. By early Monday morning rush hour, snow totals will probably range from 3 inches far south to over 6 inches on the north side of the metro area. This will be a heavy wet snow with storm total water equivalent in excess of an inch possible.
Cold air follows
As the storm moves east, snowfall will taper off later Monday morning with light snow or flurries continuing into the evening. Storm totals will probably range from 3 to 5 inches south to over 10 inches north. Behind the storm, with a strong northerly jet stream in place, frigid arctic-source air will flow south with the southern edge of this cold air mass pouring over the Canadian border into the Midwest. High temperatures in the middle 20s will be about the best Chicagoans can look forward to Tuesday through Thursday. A cold front could give a period of snow Tuesday night into Wednesday.

Dear Tom,
An office debate is raging about the meaning of wind chill temperatures and we are turning to you for clarification. When the temperature is 33 degrees and the wind is creating a wind chill of 23 degrees, will that cause water to freeze?
--James Scobie

Dear James,
It will not. Wind chill is perceived air temperature, not actual air temperature. Air removes heat from any object warmer than the air itself, and moving air (wind) removes heat more rapidly. Wind chill describes the rate at which heat is lost from our skin, not the temperature to which skin will be cooled.
Wind chill is the fictitious temperature of still air that would remove heat from our skin as quickly as the existing combination of air temperature and wind is actually removing it. Air at 33 degrees cannot cause water to freeze, regardless of a wind chill temperature well below water's freezing point of 32 degrees.

A Winter Storm Watch has been issued for a large part of the Chicago area.  For the latest on what this storm means for the area as well as snowfall totals from earlier today, follow the link below to the  WGN Severe Weather Blog.  

http://weblogs.wgntv.com/chicago-weather/severe-weather/

A snowstorm with the potential to become one of this winter's biggest appears closer to a rendezvous with the Chicago area. It could spell real trouble for travelers and commuters Sunday night and Monday. The development comes on the heels of a sun-drenched Friday which generated the city's first official temperature above 40 degrees in 26 days. O'Hare topped out at 42 degrees, Midway at 44 and the lakefront 40.

Storm evolution is complex. Much can change as one of these systems bears down on the area. But there's been growing evidence since Thursday evening the incoming storm, which only swept off the Pacific into southern California overnight, is destined to be a formidable precipitation-producer -- capable of generating a swath of heavy, wind-driven snow with accumulations that could reach a foot in at least sections of the Chicago metro area.

On Friday, not one -- but a suite of computer models run by meteorological centers based near Washington DC, Toronto, Canada, and Reading, England -- all produced predictions which shifted the incoming storm's track as much as  150 miles farther north than had been indicated earlier in the week. As noted here Thursday, a northward adjustment in the path of a storm originating over the Pacific isn't unusual. Its predicted path -- which once paralleled the Ohio River -- now takes it across central Illinois and Indiana. It's a shift which greatly increases Chicago's prospects of a direct encounter with its heaviest  snowfall. The storm's arrival Sunday night and Monday is likely to come amid strengthening northeast winds.

Gauging its potential snowfall
   
Forecasters employ a host of techniques in predicting potential snow accumulation. One, which relates snowfall to the change in temperature at 39,000 feet, yields an estimate of 9" with the current storm. Another looks at cloud structure to estimate snowfall. Modern-day computer models generate detailed analyses of the temperatures within snow-bearing clouds. Temperatures in clouds affect snowflake growth and volume and can have a huge impact on just how much snow piles up during a storm. Predictions with the incoming storm suggest an average of 11.7" of snow may fall with each inch of water the system generates.  With an average of 0.98" of water predicted to come from this storm, local one-foot accumulations aren't out of the question.

As always with incoming storms, the storm track will prove crucial. One track projection generated Friday had the system on a path across downstate Illinois and Indiana which would send a mix of precipitation -- including possible rain and sleet---into south suburban locations. But late-day forecasts seemed to suggest the zone of mixed precipitation and resulting reduced snow tallies might well occur even farther south. If true, this would place much of the Chicago area in line for the system's maximum snowfall.  The impact on morning and evening rush hours Monday and on late weekend travel from the west could be considerable -- and this system warrants careful monitoring.

A big snow Sunday night and Monday could significantly boost this month's already impressive 15.5" tally -- the city's 10th heaviest of the past 125 years up to this point in a February -- potentially propelling it into February's Top 5. But even more interestingly, a snowfall of 10" or more from the incoming storm would make this month one of only two Februarys to produce a set of double-digit accumulations. The only other time this has happened was in February 1896 when a 12.5" and 12" snow were recorded.
   
Chicago's Saturday snowmaker only a warm-up; dumped 5+" in Iowa Friday
 
Saturday's snow system is modest compared to the predicted Sunday night and Monday system -- and is just a warm-up for what may lie ahead.  The disturbance generated 5.4" in Cumberland and 5" at Greenfield -- both in western Iowa. The 3.7" which fell in Des Moines pushed that city's seasonal snow tally to 61.7" -- one of the five heaviest on record there.

Dear Tom,
You've never mentioned a large snowstorm that hit Chicago sometime between 1939 and 1941. I recall the streetcars could barely move? Am I wrong?
--Stanley Mastej, Homer Glen

Dear Stanley,
You are not wrong. You are recalling Chicago's fourth largest one-day snowstorm that dropped 14.9 inches of snow on Jan. 30, 1939. The snow began lightly around midnight and became heavy about 4:30 a.m., falling at the rate of about an inch an hour until mid-afternoon. Steady northeast winds reached 31 mph with gusts to 45 mph, piling the snow into huge drifts and snarling traffic. This storm was the city's biggest one-day snowfall until being surpassed by an 18.6-inch snowfall on Jan. 2, 1999; 16.5 inches on Jan. 13, 1979; and 16.4 inches on Jan 26, 1967 -- the first day of the Chicago champion 23.0-inch "Big Snow" on Jan. 26-27, 1967.

A major winter storm may impact the Chicago area and a big chunk of the Midwest Sunday night, Monday and Monday night. February, already the snowiest here in 29 years, threatens to get a lot snowier.  Models have shifted the track of this storm north and now suggest it is to move across central Illinois and Indiana. If this verifies, a mix of precipitation would occur in far southern suburbs while the remainder of the Chicago area would be perfectly positioned to get in on the storm's heavy snowfall.

   A lot can happen in the 2 days between now and the storm's arrival Sunday night. But here are some early numbers from a suite of computer model forecasts run the past two days.  Past experience has shown it wise NOT to focus on a single model run--nor even a few recent model runs--but to, instead, average across a whole range of models runs over several days. Also included in our analysis is a look at a snow forecast technique known as the BJ Cook technique which involves projected changes in temperatures at 39,000 ft. A big storm lifts incoming moist air to that level of the atmosphere, warming the 39,000 ft. layer in the process. Studies have shown there's a relationship between the degree of warming there and the amount of snow which falls at ground level. All available model forecasts and the Cook technique from two days of model runs lead to 29 separate forecasts of potential Chicago based snowfall (less is likely to occur south because of an anticipated mix of precip there).  The average of these forecasts is 9.8" and the range in individual forecasts runs from 3.1" on the low end to as much as 16.1" on the high end (don't focus on these extremes, as many people do, because the final snow tallied most often falls somewhere in between).

     Modern computer model projections also look at cloud physics and the vertical temperature profile of the atmosphere during snow events to yield a prediction of the storm's probable "snow-water ratio".  Current predictions put the snow/water ratio in this system at 11.7 to 1.  Applying that to the average of 1.02" of water-equivalent precipitation this storm is predicted by multiple models to produce would yield around a foot of snow over at least a portion of the metro area.

     This offers an early insight into the thinking on this storm. There is nothing about a forecast at this early stage of storm development which is yet carved in stone: These numbers--indeed the track of the storm---can change and have a large impact on what the storm goes on to produce. But I share this with you to help you understand the data which is available as of this 5 pm Friday, Feb. 20 posting. Stay with us for the latest on this storm all weekend,. The entire WGN weather team is tracking this and will keep you up to date online and on our WGN-TV & radio newscasts.

--Tom Skilling,
Chief Meteorologist

Bring the sun out in February and warming is bound to follow. That was certainly the case Thursday. The day's bright, blue skies, decorated from time to time by a few wisps of cirrus (ice clouds), was for many cause for celebration. Cloud-shrouded February had managed only 33 percent of its possible sun up to that point. The combination of unlimited sunshine and mild temperatures Thursday made it clear to many the march to spring is truly underway.

Area residents were treated to the mildest temperatures in 25 days. Highs hit 41 degrees at Midway and 45 at Chicago's lakefront. Other highs from Weather Bug sensors across the metro area included 43 degrees at Gary, 42 at Winnetka and Oak Lawn, and 41 at Morton Grove, Burr Ridge, Downers Grove and Park Ridge.

O'Hare's official 39-degree high fell just short of 40 and kept the growing string of sub-40 temperatures there going. With only 10 days left in February, Thursday's failure to hit 40 moved the area another step closer to a February without a 40-degree high at the city's official site. Only two Februarys in the past 140 years -- one 1901 and the another in 1978 -- have managed to escape without producing a single 40-degree reading. 
 
Minor snow system due Friday night; more significant storm potential being monitored Sunday night/Monday
 
Two disturbances -- the first fairly modest in scope, the second capable of growing into a storm Sunday night and Monday -- are being monitored. Each may impact Chicago in coming days.

System one, which on Thursday produced a fresh 6" cover of snow across western Nebraska near Ellsworth, sends a veil of cloudiness streaming across Chicago area skies Friday.  It's a development which is to ultimately take a toll on sunshine and, in so doing, probably restrain temperatures to levels a few degrees lower than Thursday -- though still seasonable by late-February standards. An overcast predicted to be in place by evening is to lower and thicken expeditiously Friday night, leading to light snow in the hours beyond midnight. The snow may continue at times Saturday and, because of some pockets of warmer air aloft, may mix with some ice pellets or even a little drizzle.

Potentially more eventful for the Midwest is a second system which threatens to develop into a full-blown winter storm later this weekend into Monday. That system's heaviest snow appears, based on early storm track projections, poised to sock an area from Missouri across downstate central Illinois and Indiana with a significant snow -- potentially a half foot or more.

Chicago doesn't completely escape this system's reach in current forecast scenarios. Its northernmost snows reach the city amid strengthening northeast winds Sunday night into Monday.  A series of computer-model snow estimates produces an average around 3"  in the city. It's likely there may be lighter totals north in Wisconsin border counties and that heavier amounts could fall across southern sections of the metro area.

But it's early in the storm's life cycle. The system was off the West Coast late Thursday and therefore outside the reach of the land-based U.S. radiosonde (upper-air balloon) network. It's eastward movement carries it into that network, where a more complete scan of its structure will occur, which can be incorporated in future computer forecast model runs. It's not unheard of for the track of storms like this one to be adjusted farther north as this new data becomes available. Such an outcome would allow the storm to impact the Chicago area more significantly. We'll keep you posted!

Februarys as snowy as this one have signaled above-normal snowfall continuing for the remainder of the season
 
February 2010 is currently the snowiest in 29 years of Chicago snow records. An in-house analysis of seven other snowy Februarys, with an eye toward the trend in snowfall which followed, reveals 5 of the 7 -- 71% of them -- remained snowier than the long-term averages.

After a quiet stretch of weather here in Chicago, a more active pattern will evolve this weekend that will last into the early part of next week.   For the very latest advisories, watches and warnings on what could be a significant snow maker for portions of the Midwest, check out the WGN Severe Weather Blog.

http://weblogs.wgntv.com/chicago-weather/severe-weather/

Or you can always google "WGN Severe Weather Blog".

Changes have been made to the hurricane wind scale.  The original Saffir-Simpson scale was named after the men who developed it.  Herbert Saffir was a consulting engineer and Robert Simpson was the director of the National Hurricane center from 1967 through 1973.  The updated scale now takes into account the fact that storm surge values and the flooding attributed to them, depend on the size, intensity, and motion of each storm.  Meteorologists have found storm surge values don't always stay within the ranges given in the original scale.  

In an article from NOAA, Hurricane Ike in 2008 and Hurricane Charley in 2004 are cited as good examples of this.  Ike was a very large Category 2 storm that struck the upper coast of Texas with a storm surge between 15 and 20 feet.  On the other hand, Charley was a Category 4 storm that hit Southwest Florida but only produced a 6 to 7 foot storm surge.  So the end result is that the National Weather Service has dropped the storm surge criteria from the Saffir-Simpson scale.  The scale will no longer couple the hurricane category with a specific storm surge.  However, storm surge forecasts will still be included in advisories issued by the National Hurricane Center and local weather service offices.

 

Speaking of tropical weather...

It was a tropical storm that helped first break an extreme drought over the south.  Tropical storm Fay brought much needed rain to the region back in 2008.  That storm and other wet systems along with an El Nino weather pattern and other factors, has effectively ended a drought that affected nearly half the country at its peak.  Almost 50% of the country was experiencing drought conditions in 2007 but that number has dropped to just 7% today.  Climate scientists are calling it an extraordinary comeback.

Dear Tom,
Chicago's winter is drawing to a close, but I know plenty of snow is still possible. Can you provide some hard evidence? What is the likelihood of major storms? Despite the inconvenience, I enjoy big snows.
--William Wroblinski, Chicago

Dear William,
Your desire for "major storms" is far from hopeless. As of Friday, an average of 28.4 inches of snow (73 percent) of Chicago's full-season snowfall of 39.0 inches has come down and 10.6 inches is yet to fall (Midway Airport data).
But weatherwise Chicagoans understand that averages rarely tell the real weather story. Our day-to-day weather often consists of wide swings above and below the climatological averages, and so it is with snowfall. Midway has logged 35 snowstorms of 10 inches or more accumulation since 1928, and 10 of them (28 percent) occurred after Feb. 18. And that includes a whopper: 22.3 inches on March 25-26,1930.

Chicagoans are likely to enjoy the sunshine predicted Thursday and Friday. Sun's been in shorter than usual supply in recent days -- in fact much of the month. The metro area has received 25% less February sun than a year ago and 13% less than average. With 15.5" of snow to its credit, February's been the snowiest here in 29 years. It's not surprising such a month would fall short in the sunshine department. To date, only a third (33%) of the month's "normal" sunshine has been logged -- way down from the 58% on the books a year ago. A typical February hosts 46% of its possible sun.

While the Southwest and West are awash in unseasonably mild air, cold air remains in firm control over much of the eastern three-quarters of the nation. Frost and freeze warnings were posted for a second consecutive night across north Florida and are likely to be issued again Thursday night. That area's been shivering in chilly nighttime temperatures, as an atmospheric blocking pattern continues holding cold air in place east of the Rockies. 

Florida lows dropped below freezing early Wednesday in Tallahassee (23 degrees), Jacksonville (27), Apalachicola (29) and Panama City (32), and sub-freezing temperatures were predicted a third of the way down the Florida Peninsula overnight.

In marked contrast, residents of the Southwest and West continue basking in unseasonably warm air. Phoenix topped out at 78 degrees Wednesday while downtown Los Angeles recorded 80. The mild air extended north along the West Coast and included a 64-degree high in San Francisco and 51 degrees in Seattle. 

Chicago's been snowier than Anchorage, Alaska

The winter 2009-10 pattern across North America, dominated by cold air in the east and mild air far west, has contributed to the production of more snow in Chicago to date (45.4") than the 44.4" thus far in Anchorage, Alaska.
 
Period of early weekend light snow may be followed by more important Midwest snow-maker
 
The first of two snowy spells expected to impact sections of the Midwest including Chicago in the coming week is just days away. Light snow may streak into the area for a time Saturday -- but a more substantive snow system is being monitored for late Sunday into Monday. That one's currently off the West Coast but is expected to sweep across the Rockies early in the coming weekend. The track it follows is likely to influence how it distributes its snowfall.
Projections generated by National Weather Service supercomputers late Wednesday hint at a potentially significant snow event centered on central Illinois and Indiana late Sunday into Monday -- but with snows likely to extend north into Chicago where some accumulation may also occur. A more northerly track -- with the center of the system crossing central rather than southern Illinois and Indiana -- could shift that system's most significant snowfall north into the Chicago area. That scenario will be monitored very closely in the days ahead as the Pacific system comes ashore, where its structure can be more thoroughly measured by land-based weather balloons.
 
45 of the 167 biggest Chicago snows (6"-plus) have occurred beyond this date

About a third of Chicago's measurable snows occur from this point in the season forward. And, of the 167 six-inch or greater snows which have occurred here over 125 years of records here, 45 of them (33%) have occurred from Feb. 18 forward.

Dear Tom,
If there was snow coverage in all of the lower 48 states and Alaska, as was reported, would that not mean there was snow coverage in all 50 states? I believe the tops of Hawaii's Mauna Loa and Mauna Kea always have snow.
--Jean Cavanaugh

Dear Jean,
It was reported, erroneously, that 49 of the 50 states had snow on the ground on Feb. 12, with Hawaii standing alone as the only snow-free state. Further investigation revealed that every state in the United States had at least some snow on the ground on Feb. 12. Photographs provided by hikers near the summit of Mauna Kea (elevation: 13,796 feet) verified there were a few tiny snow patches (a foot or two across) Feb. 12. Let's correct the record: Every state, 50 out of 50, reported at least some snow Feb. 12. However, please note that Mauna Loa and Mauna Kea are snow-free most of the time.

Much like the snow that has fallen this winter in many cities across the southern U.S. snow also fell in Rome last week. The city was hit by a sticking snowfall on February 12.  These pictures were taken by Fabrizio di Meo. Our thanks go out to David Lastrucci of Mount Prospect for helping us get permission to post these pictues from  Fabrizio.

Mary Koehler sent us these great weather photos that were taken on Valentine's Day in Wisconsin's Door County. We love these photos Mary! Thanks so much for sharing.

The pictures below were taken in the Pittsburgh area after the historic snowstorm that walloped the East Coast earlier this month.  The photos are from Paula Oltrogge, who took a picture of a neighbor's tree with broken limbs as a result of the heavy snow. She also witnessed deer who seemed to be "swimming" in the snow since it was so deep. Thanks Paula for the great photos!

With each passing day, the momentum for seasonal warming increases. Days have grown longer by 94 minutes since Dec. 21 and are to lengthen another 79 minutes in the coming month. All the while, the sun's rays arrive with greater energy as it follows a trek across the sky each day higher and higher above the horizon. This shift in the sun's daily trajectory overhead has allowed sunlight intensity in Chicago to more than double since December. But these aren't the only factors pushing toward warming. The sun has risen in the past month across arctic regions of North America after a 2 month absence. This will eventually decrease the supply of available cold air by contributing to warming over the northernmost reaches of the continent.

But even with all these factors at play, formidable obstacles to warming must be overcome---something that's obvious in the fact Wednesday is to mark the 12th consecutive day with high temperatures which fall short of typical mid February levels. The widespread snow pack in place across the 56.3 percent of the country is among them. It reflects incoming sunlight, which might otherwise warm the air, back to space. Clouds also interfere with warming by blocking sunlight. Perhaps most significantly, the intransigent atmospheric blocking pattern at arctic latitudes from Greenland to Alaska, which has forced the reservoir of cold air  normally situated from the North Pole into Canada, south into the U.S.---particularly areas east of the Rockies. This blocking shows little sign of relaxing in the coming two weeks. During that period, there may be a few comparatively brief up-ticks in temperature thanks to the growing strength of sunlight---but there's little evidence the overall pattern is likely to undergo a massive change any time soon. This appears to limit prospects for strong warming through the remainder of February and into early March. In fact,  colder air may replace the moderately intense chill currently covering Canada in the next week allowing it to extend icy late-season tentacles into the northern tier of states next week,  threatening a reinvigorated storm track along its southern periphery.
 
Chicago in the midst of its snowiest February in 29 years
 
Flurries are to flutter earthward here in spells Wednesday--- particularly in the Indiana/Michigan snow belt. This takes place in a February which is already the snowiest since 1981---29 years!  An official 15.5-inches is on the books at O'Hare--- three times the long term average of 5.2 inches and nearly 78 times the 0.2 which February had to its credit the same time a year ago. A review of seven previous seasons in which February was incredibly snowy reveals five---71 per cent of them---continued on a snowier than normal path. Weather history here reveals a quarter (27 percent) of Chicago's biggest late season snows (6" or more) have occurred beyond Feb. 17.
 
 
Beyond Wednesday's Indiana lake snow showers, this weekend is being monitored for a possible snow system
 
Many questions remain---but there continue to be hints a snow system could sweep northeastward into the Midwest from the Plains this weekend. Much will depend on the track the system ultimately follows and on its strength. Stay tuned.
 

Dear Tom,
My brother who is prone to exaggeration was in a whiteout in Minnesota and he claims it was a very frightening experience. I am skeptical.
Robert Malik, Chicago

Dear Robert,
A whiteout in its true form is an atmospheric optical phenomenon so overwhelming that it brings life-threatening disorientation. Whiteout occurs over snow-covered ground and beneath a uniformly overcast sky when the amount of light coming down from above equals that reflecting up from the snow.

Disorientation results when such illumination is accompanied by zero visibility in dense fog, falling or blowing snow or a combination. During whiteout, a person is engulfed in a uniformly white glow and neither shadows, horizon nor clouds are discernible. A sense of depth perception and orientation is lost, and only very nearby dark objects are visible.

Your brother's description is believable.

Former WGN-TV Weather Center intern Monika Bec sent us this impressive shot of the north side of Chicago's lakefront this past Sunday, Feb. 14.

Monika tells us:

"Sunday was beautiful wasn't it? So nice and sunny. At times, in the sun, it felt like the 40s we haven't had! What a lovely Valentine's Day it was! Went to the Hancock Observatory Sunday midday and enjoyed the day walking around the city. We need to warm up soon!"

Yes---warmer weather would be nice indeed. Thanks for the great shot Monika!

Jerrold Petrizzo from Lemont sent us these icicle pictures taken Tuesday afternoon.

Thanks for the pictures Jerrold!

The Kustusch Family from Bedford, Texas sent us this shot of  the recent snowfall which whitened areas of Texas.

They tell us:

"After a record-breaking snowfall, we introduced "Cubbie-Man" to our Texas neighbors. It reminded us of home."

Thanks for the great picture!

Carol Moukheiber of Lombard took this photo on Feb 10.
She tells us:

"Looks like an engagement ring. Very appropriate for Valentine's Day weekend. Nice to see when trying to clear all the snow !!!!!!"

7 year old Kyler Czerwin from sent us these wonderful pictures. Kyler tells us:

"I thought you would like to see this photo of my igloo that my dad made it took him three days of carving it out."

That's quite an igloo Kyler! Thanks for sharing these pictures!

Chicago native Lisa Roth who lives in Cleveland sent us these pictures of the snow there. Lisa tells us:

"It is snowy and we are in the snow belt so it just keeps coming and coming!"

Thanks for the great shot Lisa!


Photo courtesy of Lisa Roth, Cleveland, Ohio

The National Weather Service wants you!  Severe weather season is right around the corner and we need more eyes to the skies.  If you are interested in becoming a storm spotter, the National Weather Service will be holding several severe weather spotter classes between now and the end of April.  Just click here to see a schedule and find a class near you.  The class takes between one and half to two hours to complete.

In response to the Plainfield tornado on August 28, 1990, the Chicago office of the National Weather Service, the DuPage County office of Emergency Management and the College Of DuPage all joined forces to create the Multi-County SkyWarn of Northeast Illinois.  Thousands of spotters spread out across 15 counties have received training and are now one of our first lines of defense during severe weather. 

Click here for a basic severe weather spotting guide.

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The weather pattern dominating North America has an upside-down quality to it. Perennially warm spots are running surprisingly cold while some cold locales are experiencing unprecedented warmth. It was warmer Monday in Anchorage, Alaska, where the temperature hit 44-degrees, than it was here in Chicago with a 28-degree high. Juneau, Alaska's 38-degree low Monday morning was milder than lows of 35-degrees at New Orleans, Louisiana and Daytona Beach, Florida. And to add to the meteorological intrigue, the bursts of snow  responsible for half-inch accumulations over parts of the Chicago area  Monday, swept into the area from the northeast rather than the west--the typical route snow and other weather systems follow into the area.

Chicago missed the latest significant snow system to sweep the Lower 48 Monday. It buried Ohio and sections of downstate Indiana--- including the Bloomington area---beneath as much as 10 inches of snow, at the same time unseasonably mild weather and an exasperating lack of snow continued to dog winter sports venues at the Vancouver Olympics. Temperatures soared to 53-degrees Monday in Vancouver and to the upper 30s to the north at Whistler, British Columbia, site of a number of Olympic skiing and snowboarding events. The warmest January on record there and the mildest  February in 17 years has reduced the typical 80-inch February snowpack to just 35 inches, as more rain than snow has rendered slopes icy and bumpy.  

An atmospheric blocking pattern is behind the unusual weather

A blocking pattern which extends from Greenland across northern Canada---the product of a huge pool of comparatively mild air aloft draped across much of the arctic region---shows little sign of relaxing in coming weeks. As a result, chilly weather is likely to hold tight in Chicago. High temperatures Tuesday flirt with 30-degrees---which, while hardly extreme, will fall 5-degrees shy of historic norms, making it the 11th consecutive below normal day. More than half (57 percent) of meteorological winter days (since Dec. 1) have been below normal.
 
Cold hasn't been barbaric, but it has dramatically slashed the number of mild days
 
With just two weeks to go in the three month meteorological winter (December through February) period, it's clear the books will close on a colder than normal season this year. Since Dec. 1, Chicago's temperature has run 2-degrees below the long term average. That hardly qualifies as extreme cold. But, the persistence of the chill has had its biggest effect on the season's mildest days. Only six days of 40+-degree "warmth" have been logged to date this season---25 percent of the average 24 days over the past 81 years. There's been only one winter season since 1928 with fewer 40s to date--- 1978-79 with only five 40s by now. Chilly as it's been, it's worth noting that this season has averaged 3-degrees warmer than last.
 

Dear Tom,
It is starting to look like we may not reach 40 degrees this February. Has that ever happened before?
--Michael Donlan

Dear Michael,
Considering that the city's average high temperature climbs to 39 degrees by the end of the month, it is extremely rare, but it has happened twice before since records began in 1871 -- February 1901, with a high of 35 degrees, and February 1978, which maxed out at 37. Two other Februaries have come close; February 1920 and 1989 with just one day each. February 1989 was unusual in that in was 52 degrees Feb. 1 and then never touched 40 degrees for the rest of the month. On the warmer side, February 1998 stands out as having 25 days in which temperatures topped 40 degrees, highlighted by a spring-like 63 on Feb. 26, 1998.
 If this month's chilly trend continues, it stands to become the city's third February that failed to record a 40-degree day.

We start this week off with a little light snow and temps a bit below average.  In other words, this is going to be a quiet but cold week.  It looks like more of the same for the next two weeks at least.  The Climate Prediction Center's outlook for the next two weeks is calling for below average temperatures and below average precipitation. 

 

The NAO or North Atlantic Oscillation is a "is a large scale seesaw in atmospheric mass between the subtropical high and the polar low".  It has turned out to be a good indicator for long term forecasts.  The NAO index forecast seems to suggest a cold pattern for the next two weeks or so.   Just a few days ago some of the computer models were suggesting a major snowstorm in the midwest for this weekend but they have recently weakened the storm and are keeping it further south. 

Stay tuned.....

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Cold weather has been the rule in Chicago this month -- not extreme, but persistent. Highs have varied only nine degrees from 26 on Feb. 10 to 35 on Feb. 5. The week ahead promises more of the same, and it is likely that a week from now the city will still not have recorded a 40-degree high by Feb. 21 -- the latest such occurrence in 31 years, when it finally reached 42 on Feb. 23, 1979.

Light snow could bring up to an inch or so of accumulation here Monday into Tuesday as a more significant storm lays a blanket of heavy snow across the southern Midwest into the Ohio Valley. A second storm later this week poses another snow threat, and the city could be on the north edge of the significant totals.

Snow, cold lingers in South

Wintry weather continues across the South with more snow and cold. Winter weather warnings and advisories are posted Monday across a broad area from Arkansas and Mississippi east to Georgia.

Record afternoon cold gripped Florida again Sunday with highs from the middle 50s to lower 60s. Late Sunday afternoon it was warmer at the Winter Olympics in Vancouver, 54 degrees, than at Tampa, 52.

Dear Tom,
I recall a severe hailstorm moving through the Chicago area on May 17, 2006, that drastically dropped temperatures. Am I correct?
-- Robert Skurski

Dear Robert,
Strong thunderstorms that developed ahead of a cold front swept through the Chicago area on May 17, 2006, pounding nearly all sections of the region with hail that ranged in size from pea to golf ball. Some of the largest hailstones (1 inch or greater) were reported in Des Plaines, Glenview, Rosemont, Cicero, Wauconda and in the city of Chicago.
Before the thunderstorms hit, temperatures had climbed into the lower 70s, but the mercury plunged in the storm's wake with temperatures dropping into the upper 40s and lower 50s. One reason the storms were such prolific hail producers was a low 8,000-foot freezing level which allowed the hail that formed in the storm's vigorous updrafts to reach the ground without melting.

The snow continues to pile up across the southern United States while parts of Alaska are experiencing a "snow drought".  

To see some of the rather staggering snowfall numbers, follow the link below and check out the WGN Severe Weather Blog.  Or you can always Google "WGN Severe Weather Blog".

http://weblogs.wgntv.com/chicago-weather/severe-weather/

Vancouver continues to experience above normal temperatures this Sunday morning while much of the southern United States is shivering.   

At 7:00AM CST, the temperature in Vancouver, British Columbia is 48 degrees fahrenheit, 3 degrees warmer than the 45 degree reading Miami is waking up to.  

In northern Florida, Freeze Warnings and Wind Chill Advisories are in effect as temperatures hover in the 20's.  

Snow is expected to return to sections of the Florida Panhandle tonight for the second time in less than a week.   A winter weather advisory has been posted for portions of southern Alabama and the Florida Panhandle. 

Clouds will be increasing in Chicago on Valentine's day but the weather should be dry until some snow moves in at night, as an unusual southwest push of moisture, having origins over the north Atlantic near Greenland, moves into the area. The snow should  begin Sunday night and continue intermittently into Tuesday. While not expected to be heavy, snow could accumulate a few inches with enhanced totals near the lake.  A more significant storm, which brought up to 10.5 inches of snow to North Dakota Saturday, will miss Chicago but drop a band of heavy snow from Missouri into the Ohio Valley on Sunday/Sunday night and bring another accumulating snow to Washington D.C. on Presidents Day.
 
Big chill follows southern snow

Friday's snowstorm in the Southeast is history but it has left a record chill in its wake. Up to 2 inches of snow fell in the Florida Panhandle, while 4 to 9 inches coated areas from Arkansas and Louisiana to the Carolinas and Virginia. High temperatures Saturday were mainly in the 40s.  In central Florida, 52 degree record low maximums  were recorded at Orlando, Melbourne and Vero Beach.

 

Dear Tom,
Growing up in Chicago I remember a severe ice storm in January 1965. I don't remember an ice storm of that caliber since. Do you have any details?
--Glen Grant

Dear Glen,
The ice storm that hit the Chicago area on Jan. 23-24, 1965, is considered by utility companies to be one of the worst on record, second only to one on New Year's Day in 1948. Damage from the 1965 storm was estimated to be in the millions of dollars with the north and west suburbs hardest hit. Power was out for days in many areas. Damage in the city was limited but the ice coated almost everything, creating a glistening fairyland appearance. Icy roads made travel nearly impossible, forcing many schools and businesses to close, and hospitals reported a rash of injuries from falls. Countless trees were toppled and many basements flooded due to the lack of power to run sump pumps.

Winter Weather Advisories have been posted across portions of southern and western Illinois for tonight and Sunday.   A Winter Storm Watch has been hoisted for portions of Indiana and Ohio.  For the very latest, follow the link below to the WGN Severe Weather Blog. 

Or, you can always Google  "WGN Severe Weather Blog".

http://weblogs.wgntv.com/chicago-weather/severe-weather/

Thanks to Michael Gesmond who moved to James Island in the Charleston S.C. area  from Portage, Indiana in 2006. They received about 3 inches of snow Friday night  which brought traffic to a complete standstill. Michael says the storm reminded him why he left the Chicago area.

Photos by Michael Gesmond

The extraordinary rash of snowstorms which have swept the U.S. in recent weeks, many generating record snowfall, have produced one of the country's most expansive snow packs in recent memory. National Weather Service researchers charged with monitoring the country's snow cover and its water content estimated Friday that more than 67% of the Lower 48 sat beneath a veil of snow. Hawaii, despite the presence of mountains which can and often do become snow-covered in winter, is the only state not to report at least some snow on the ground. The snow has been so widespread in recent weeks, even perennially snow-free Florida has failed to escape. De Funiak Springs, in the state's panhandle near the Alabama border, reported a 1" snow accumulation late Friday afternoon at the same time a thundery squall line in warmer air to the south was diving southward the length of the Florida peninsula unleashing driving rains and 70 mph gusts.

The meteorological mayhem in the Sunshine State was the product Friday of the same powerful winter storm, which only a day earlier walloped the Dallas/Fort Worth metroplex with an all-time calendar day record of 12 to 14" of snow.

The eastbound system spent Friday burying areas unaccustomed to snow beneath rare accumulations. Up to 8" fell at De Kalb, Miss., while thousands were reported in the dark late Friday across Charleston, S.C., as wind and wet snow brought down power lines. Much of the city's downtown area was without electricity Friday evening. Just west, snowfall reached 7" as night closed in on Columbia, S.C. A motorist in nearby Chapin reported taking an hour to travel just 10 miles. All forms of travel were severely impacted across the Southeast. Heavy snow forced the cancellation of thousands of flights in Atlanta and across the region.
Rapid intensification of the sprawling storm was underway late Friday. A NOAA buoy off the northeast Florida coast 42 miles east/northeast of St. Augustine reported winds which gusted to 52 mph as barometric pressure readings, a gauge of storm intensity, plunged an eye-catching 11 millibars -- from 29.71" to 29.38" in under two hours. The storm is predicted to move out to sea Saturday.

More snow for DC?

A new low pressure drops southeastward through the Plains Saturday and Saturday night, developing a swath of snow from North Dakota southeastward into Missouri and southern Illinois.  While this system is likely to remain west of Chicago, it threatens to spin up into yet another snow-producer for the Nation's Capital early next week.
     
Chicago's next snow due Sunday and Monday
 
The Valentine's Day weekend is to remain meteorologically quiet for Chicago with plenty of daytime sun Saturday and Sunday and moderately chilly mid-February temperatures.  But an unusual southwestward push of moist Atlantic air into Chicago from Canada Sunday night and Monday is to deliver the area's next snow.

While most of Chicago's weather arrives from the west or south, the moisture behind the next snow system has origins over the North Atlantic and the Davis Strait -- which sits between northeast Canada and Greenland.  A rare jet stream configuration, which features upper steering winds that flow from the Atlantic westward into the Midwest, is driving the unusual pattern and is to be joined by by north to northeast low-level winds expected to blow into the city Monday off Lake Michigan, potentially enhancing snowfall.

Dear Tom,
Chicago's range between all-time temperature extremes is 132 degrees. How does that rank for U.S. cities and the world?
--Robert Herzfield

Dear Robert,
Chicago's range of temperature extremes is a robust 132 degrees, from a low of minus 27 on Jan. 20, 1985, to a high of 105 on July 24, 1934; a testament to the city's vigorous continental climate. Fort Yukon, Alaska, leads all U.S. cities with a range of extremes of 178 degrees, recording an all-time low of 78 below zero to a high of 100. According to the Guinness Book of World Records, worldwide honors go to a location in eastern Siberia, a region often referred to as the Northern Hemisphere's "Cold Pole" where the city of Verkhoyansk, Russia, sports a record low of minus 90 and a high of 99 degrees -- an incredible 189-degree span.

These pictures of the snowbound Dallas area were sent to us by Gerald savage, formerly of Kankakee. Gerald lives in Red Oak south of Dallas.

 

  

Photos by Gerald Savage

Thanks to Tom Sidener of Mesa, Arizona for sending along these great shots taken in the mountains of eastern Arizona near the New Mexico border between Alpine and Hannagen Meadow

 

Photos by Tom Sidener

Snow fell yesterday in the deep south blanketing Dallas with almost 8 inches.  Snow also fell in Jackson, Mississippi.  This southern stream storm is expected to produce snow in such unlikely areas as Pensacola, Florida & Myrtle Beach, South Carolina.  By the end of the day, there could be snow on the ground in all 50 states.  Yes, even Hawaii has snow.  Don't forget that Mauna Loa is nearly 14,000 feet high and can get snow any time between August and May.

Speaking of snow, if you are like me, you are tired of shoveling your driveway only to find a big hump of snow at the end of it after the plows come through. 

 

 

The Chicago Tribune has a helpful graphic with tips on how to avoid this.  No shoveling for us through next Thursday.  We might see a few flurries today and a little light snow late Sunday or Monday but little or no accumulation expected.

 

www.facebook.com/TimMcGillWeatherGuy

 

http://twitter.com/WGNWeatherGuy

 

The latest in the this season's parade of record-breaking storms had no sooner exited the mid-Atlantic early Thursday when the snows of the week's second storm---this one on a more southerly track---swept into north Texas and southern Oklahoma. It was to prove one for the books there. By late afternoon, 7.9 inches of snow had fallen on the Dallas/Fort Worth metroplex---more than on any other single day in 112 years of weather records. That total eclipsed the previous record of 7.8 inches first recorded on Jan. 14, 1917---then again on Jan. 15, 1964. And the snow was far from over. By 10 p.m.  in Dallas---just five hours later---snow was still falling heavily and the tally had jumped to 9.4 inches. For more than 13 consecutive hours, snowfall was so heavy in the north Texas metropolis, visibilities were slashed to a half mile or less.

The big totals weren't limited to Dallas/Ft. Worth proper. To the northwest in Denton, 12 inches had fallen by late evening and Cottondale, 67 miles to the northwest, was hit by 11.5 inches. 

The eastbound storm threatened to spread rare accumulating snows across a wide swath of the Deep South---including New Orleans' northern suburbs, Mobile, Ala. and even Pensacola, Fla., where an inch or two was predicted to stick on grassy surfaces. The full brunt of the storm threatened far heavier accumulations in Jackson Miss. (3-6 inches) and Birmingham Ala. (up to 3 inches). Winter storm watches were up Friday and Friday night for Atlanta and Savannah in Georgia and for Columbia and Charleston in South Carolina.
 
Quieter pattern for Chicago: Nights frigid but stronger February sun a factor by day
 
A minor disturbance threatened Chicago with cloudier skies and a few flurries Friday, a big change from Thursday which logged 98 percent of its possible sunshine making it the area's sunniest day in four weeks. Despite Thursday's sub-freezing 30-degree high, icicles dripped and the foot of snow which fell earlier this week continued settling and even melted a bit.  The snow depth at Midway Airport slipped from 9 inches to 6 in just a day's time.

Between January and February, sunshine in Chicago doubles in strength. The higher trek the sun follows across area sky allows the delivery of stronger, more direct rays and is the reason chilly air masses don't always feel quite as cold as their late December or January counterparts.

 
58 percent historical probability of  a 60-degree temperature in the coming 30 days
 
Winter's far from over. Computer models are hinting that although Friday's flurries and the potentially lake-enhanced snow showers predicted to lock in Sunday night into Tuesday, will most likely  produce only modest accumulations. That could change in Week #2.  Some early projections hint two storm systems could cross the area and possibly produce significant snowfall close to Chicago.

Despite that, it's worth noting that 58 percent of years have produced a 60-degree temperature in the coming 30 days (by March 13)---and that the first 70-degree temperature may be only a little over 40-days away if their arrival dates parallel historic trends.
 

Dear Tom,
I noticed that the snow Monday and Tuesday in Arlington Heights had a distinct bluish cast. It reminded me of the color of glacial ice in Alaska. What would cause that?
Dale Hugo, Harper College, Palatine

Dear Dale,
It's due to the physics of light reflection and absorption. Normal light (such as sunlight) consists of a blend of all colors of the spectrum, and our eyes interpret that "blended" light as white. The color of any given object is determined by the color of the light that it reflects. For example, a red sweater appears red because its cloth absorbs all colors of the spectrum except red light, which it reflects. Snow is white because it uniformly reflects the full spectrum of colors. However, most of the spectral range of colors is absorbed when light penetrates into snow or ice, but blue light is absorbed somewhat less. Any light that emerges will therefore have a slight bluish tint.

Brandon Kilgore from Grand Prairie Texas sent us this picture of the snow in Texas. He tells us:

"I watch you on WGN America and through you might be interested to see these snow men on a record setting day here in the Dallas Fort Worth Metroplex. There is about 6-7 inches on the ground here at my home in the Dallas suburb of Grand Prairie Texas."
 
Thanks for the great shot Brandon!
 


Photo courtesy Brandon Kilgore, Grand Prairie, Texas

It seems almost unfathomable in Thursday morning's chill that Chicago's earliest 70-degree temperature occurred 11 years ago---on Feb. 11, 1999. That warm spell, brief as it was,couldn't have come at a better time for winter-weary area residents. Only 5 weeks earlier, the city had been hit hard by a snowstorm which produced the 2nd heaviest snow since records began in the 1884-85 season.  (That January 1999 storm, replete with 50+ mph wind gusts, smothered the area beneath 18.6 inches of snow.) The city's first 70-degree reading of the year has occurred on average on or about March 24.

Temperatures at that level are the last thing on the minds of many across the Chicago area Thursday morning. Clearing skies and diminishing overnight winds have allowed temperatures to dive into the single digits and teens---a temperature plunge spurred in part by the presence of the season's deepest snow pack.

Chicago's 2009-10 seasonal snow tally has reached 45.1 inches in the wake of Tuesday's record snow---a total which ranks 9th snowiest of the 125 on the books to date. It's nearly twice the 24.9 inches which has typically occurred by now.

Tuesday's 12.6 inches of snow at O'Hare over becomes the city's single heaviest calendar day February snow on record. The tally also qualifies as the 7th heaviest calendar day snowstorm in over 125 years of observations. 

Think snow's bad here? Mid-Atlantic reeling in midst of snowiest season on record!
 
The Nation's Capital, where schools, businesses and even a parts of the Federal government shut down in blizzard conditions Wednesday, is now home to a deeper snowpack---28 inches of it---than in either Anchorage Alaska (20 inches) or Marquette Mich. (27 inches). The latest snowstorm to hit the Mid-Atlantic generated 10.5 new inches of snow in Washington, D.C. 19.5 inches Baltimore, 14.4 Philadelphia and 12.5 in New York's Bronx Wednesday.

Seasonal snow tallies in the region are stunning.  In Washington, where 15 inches falls on average during an entire season, 55.6 inches is now on the books---making this the snowiest season on record. The nearly 20 inches of snow which fell Wednesday on Baltimore in the midst of howling, blizzard-strength winds sent that city's seasonal snow total soaring past 72 inches. Seasonal snow tallies have also reached new all-time highs in Philadelphia, Wilmington DE, and Atlantic City, N.J.

It's now the third consecutive snowier than normal season
 
Some light snow reaches Chicago again Friday evening and night.  But, a new system Sunday night and Monday will have to be monitored for possibly more substantial snows. All of the snow of late has pushed Chicago's seasonal snow above normal for a third consecutive winter. 

Dear Tom,
Can you explain how visibility is determined?
John A. Wilson, Sycamore
Dear John,
Prior to automation, visibility was determined by weather observers who noted the most distant object visible at a known distance, such as a building, water tower or geographical landmark. After dark, the observer relied on unfocused lights as darkness made most daytime objects unusable. In recent years automated weather observing systems have been implemented and complex algorithms compute the visibility using data obtained by bouncing a laser beam back and forth between a transmitter and a receiver. Observers can still augment the computer visibility value during rapidly changing conditions or when the computer measurements seem inaccurate. Ten miles is the maximum visibility reported by the automated system, a value considered ample for aviation safety.

Thanks to Bill and Nancy Beach who forwarded these pictures from snowbound Washington D.C. The area was hit by 10 to 20 inches of snow today with area totals for February alone ranging up to 45 inches.

Photos by Bill and Nancy Beach

Thanks to Jerrold Petrizzo for this shot of a snow-covered landscape in Lemont.

Photo by Jerrold Petrizzo

Thanks to Mario Ortiz of Evanston who sanpped this picture after last night's heavy snowfall. It looks like a novel way to remove snow and sure beats shoveling.   

Thanks to Anne Wolf of Park Ridge for sending us this shot of her snow-covered back year with the snow perfectly grooming everything in the yard. Anne remarked that the snow on the patio reminded her of icing on a cake.

Photo by Anne Wolf

Photo by Ryan Muench

Thanks to Matt piechota for passing this shot taken during the height of the snowstorm on Tuesday evening.

 

 

Photo by Matt Piechota

Forecasters out east have coined the phrases "Snowmageddon" and "Snowpocalypse" to describe the nasty series of storms they have experienced this winter.  New York City has a blizzard warning in effect today.  Washington DC has seen 48.8" of snow so far this season (not including today's storm).  That is almost five times more than they see in an average winter to date.  Ironically, a senate hearing on global warming was postponed in DC because the snow.

Our snowfall for the season is getting impressive also.  The 12.6" of snowfall at O'Hare yesterday ranks as the 7th biggest single calendar snowfall on record.  It was also a record snowfall for the date and the most snowfall for a single day in February.  It brings our seasonal total up to just under 45", nearly twice the average to date.  Tuesday's storm hit northern Lake County the hardest with 14" in Antioch.

 

 

As if the snowstorm itself wasn't enough to talk about today, we experienced a 4.3 magnitude earthquake centered near DeKalb this morning.  Before you push the doomsday clock forward though, keep in mind that earthquake's aren't that unusual for Illinois.  Click here for a look at the history of Illinois earthquakes.  I experienced my first earthquake early on the morning of April 18, 2008 when a 5.4 earthquake hit downstate Illinois. 

 

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With bursts of heavy snow that lasted for hours Tuesday evening, O'Hare airport officially recorded 12.6 inches of snow on Tuesday, with snow still occurring as Wednesday began. This is the biggest snowstorm, at O'Hare since last year when 12.0 inches fell in a 2-day storm on January 9-10 2009. Much of the snow came during the evening hours when snow was falling at  the rate of about about one inch per hour. Through 7 pm O'Hare had logged only 5.1 inches of snow.

The 12.6 inch snowfall on February 9 marks the city's biggest official calendar day snowfall since 18.6 inches fell on January 2, 1999.  This is also the most snowfall ever recorded in a calendar day in February in Chicago breaking the old record of 11.5 inches on February 18, 1908. Midway picked up 8.8 inches for the day making this the 4th greatest February calendar day snowfall on record there.

Snow, which had fallen steadily much of the day at little more than a moderate clip, suddenly intensified late Tuesday. What had been a fairly innocuous late winter snow across the Chicago area through mid-afternoon suddenly took on the trappings of the significant winter storm which had been predicted--particularly in the counties lining Lake Michigan's Wisconsin and Illinois shorelines. Thoroughfares on which road chemicals had worked so well much of the day, quickly covered with snow, rendering them treacherous as night fell. 

By late evening, Lake County's Antioch, just south of the Wisconsin line, sat under a fresh 14-inch snowpack while just to the south in Round Lake Heights, a 12-inch snow glistened beneath streetlights, which dimmed as each wave of heavy snow passed. Other snow totals in Mount Prospect (11.3 inches), Buffalo Grove (11.0) and Mundelein (10.5) moved within striking distance of a foot---and totals of 9.6 inches at Beach Park, 9.4 at Oak Brook, 8.3 at Downers Grove as well as the official in-city totals of 8.3 at O'Hare and 7.0 at Midway--seemed likely to surge still higher overnight as late evening snows grew in areal coverage and intensity. Weather radars from Chicago to Green Bay indicated clusters of heavy lake-effect snow were in the process of consolidating into an elongated 260-mile band---extending from east of Door County, Wisconsin south the length of Lake Michigan into northeast Illinois. The feature, referred to by meteorologists as a "lake-snow plume," threatened additional accumulations of snow up and down the western shore of the lake during the night.

Lake snow plumes form as low-level winds converge over warmer lake waters. These converging winds lead to a pile-up of air at the surface which has little option but to rise, cooling and becoming saturated as the lake moisture evaporated in it condenses.  Towering clouds form from which locally intense snows fall. With winds guiding these lake-effect clouds southward over lake waters for an extended distance, the chance for moisture to accumulate is huge. The snows which fall at the end of such a long plume of saturated air can be quite formidable---as northwest Indiana residents are to find out much of Wednesday as these lake snows slowly shift east.

Wednesday is to open with the heavy snows of the plume riding into northwest Indiana's Lake and Porter Counties---but shifting gradually eastward to La Porte County by late in the day.
    
Third consecutive snow season to top historic norms
 
Tuesday's 8.3-inch snowfall at O'Hare pushes the site's seasonal snow tally to 40.5 inches---well above the 38 inches of snow considered "normal" in a full season. It's the third consecutive Chicago snow season to exceed the normal full-season tally.

Boston and New York missed last weekend's big snow---but not this one

Washington, Baltimore and Philadelphia were all buried by record-breaking snows last weekend which by-passed Boston and New York. That won't happen with the current storm. Heavy snows and howling winds are predicted in both cities Wednesday.

Dear Tom,
My parents, now deceased, drove to Florida in January 1938 in a two-seat open car. They told me it was cold and the closer they got to Florida, the colder it got. Could you please tell me about that Florida cold spell?
Carol Ritchie, Des Plaines

Dear Carol,
We tapped the resources of weather historian Frank Wachowski and he dug into his archives to retrieve the information you seek. Utilizing Climatological Data, 1938 (a publication of the U.S. Weather Bureau), Wachowski says your parents undoubtedly had a cold drive.

Periods of very chilly weather gripped Florida and much of the Southeast during the latter half of January 1938. In Florida, the month's closing week was especially cold. Readings sank below 20 degrees in northwest Florida and frosts were widespread. Snow flurries dusted several Gulf Coast stations on Jan. 26.

Thanks to Jay Kleeman for passing along this shot of a very snowy night in Mount Prospect where snow totals were approaching 12 inches.

Photo by Jay Kleeman

Snow continues to fall across almost the entire Chicago area this afternoon.  The Blizzard Watch will not be upgraded to a Blizzard Warning, but conditions are expected to deteriorate as we head into this evening as areas of heavy "lake enhanced" snow are starting to develop over some lakeshore communities.

Up to 8" has already fallen north of Chicago in Lake County.

For the very latest, follow the link below to the WGN Severe Weather Blog. 

http://weblogs.wgntv.com/chicago-weather/severe-weather/

Thanks to the Frystak family in snow-covered Antioch for passing along these pictures. More than 8 inches of snow had fallen there through late afternoon with the flakes still coming down at a heavy rate this evening.

  

 

Photos by the Frystak Family

Thanks Cliff Lyde of Midlothian for passing along these shots from today's snowstorm. Snowfall there was closing in on 6 inches when these shots were taken.

   

Photos by Cliff Lyde 

A well warranted Winter Storm Warning remains in effect for the entire Chicago area.  In addition, the National Weather Service has issued a Blizzard Watch for some southern suburbs.   For updated snowfall totals and the latest on the Blizzard Watch, follow the link below to the WGN Severe Weather Blog

 http://weblogs.wgntv.com/chicago-weather/severe-weather/

A February snowfall of 10" or more occurs on average only once every 16 years in Chicago. Only five such storms are on the books at Midway Airport in the 81 years since 1929.  Tuesday's storm may well become the sixth!  Before it finishes with the Chicago area, 8 to 14 inches of snow may accumulate--the season's heaviest to date and the biggest storm to occur here since nearly a foot fell here over two days just over a year ago in late January  

The current system's impact on the Chicago area is only in its early stages as Tuesday gets underway. Three rush hours may ultimately be impacted by the system--none more than Tuesday evening's when snowfall will be at its height and winds will be gusting to 25 mph--strong enough to begin sending the additional 4 to 7" of snow predicted to fall Tuesday airborne in some open areas surrounding the city. That's also the period in which an infusion of lake moisture is to begin, supplementing snowfall. Lake enhancement of snowfall could end up spanning 10-14 hours, extending into the opening hours of Wednesday morning even as non-lake-effect snow tapers to passing flurries at inland locations. It's an important reason this storm's heaviest snow totals are predicted to occur in lakeside counties of Illinois, Wisconsin and Indiana.  

Explosive intensification of the storm is predicted by computer models later Tuesday as a secondary center forms off the mid-Atlantic Coast. Storms intensify when air rushes aloft at increasing speed. Ground-level winds strengthen as part of this intensification process. The rate at which air ascends increases, encouraging air to rush in from the storm's periphery at faster speeds to replace the upwelling of air at the heart of the storm.

The impact of the current storm's intensification across the Chicago area could become most noteworthy Tuesday night when winds approach their peak, gusting as high as 30 to 40 mph, particularly in areas surrounding the city.  Winds of that strength should easily lift snow and hurl it through the air, producing near-blizzard or blizzard conditions. A blizzard is defined by the National Weather Service as three or more hours with winds gusting to or above 35 mph, and during which blowing snow reduces visibilities to a quarter mile or less. The density of structures such as homes and buildings in the city and close-in suburbs often generates enough drag on the moving air to subdue velocities there.  But this doesn't happen in open areas surrounding the city, and these areas appear particularly vulnerable to potentially significant blowing and drifting snow Tuesday night.
 
Latest storm producing 1,300-mile corridor of snow; "Bosnywash" corridor being hit hard again

As unbelievable as it may seem, the Nation's Capital--where a snowfall of 1 to 3" can cause serious travel problems--is under the meteorological gun once again. Just three days from one of the region's worst blizzards in history, forecasters are predicting 10 to 20 inches of new snow may fall as winds strengthen later Tuesday. This promises a rash of new travel problems.

Dear Tom,
What do the lines on weather maps mean?
--Jenna Jamieson (5th grade), Bloomingdale, Ill.

Dear Jenna,
Meteorologists use weather maps to display information such as temperatures, air pressure and winds over large areas. The maps give forecasters the ability to see the big weather picture and, at a glance, to understand "what's going on" with the weather. That information is the starting point in the preparation of weather forecasts. Many different lines are drawn on weather maps, but the most common ones are called "fronts." Fronts show the boundaries between different kinds of air masses (such as hot and cold, or humid and dry). Lines called isobars frequently appear on weather maps as well. Isobars connect locations that have the same air pressure, and they show where the air pressure is low (usually with stormy weather) or high (usually with fair weather).

The entire Chicago metropolitan area is being placed under a winter storm warning effective from this evening through noon on Wednesday. Previous the winter storm warning had been in effect only for counties close to Lake Michigan where lake-enhanced snowfall was expected to boost snowfall total and surrounding areas were under a winter weather advisory. The warning area was expanded because strong winds are expected to develop gusting to 35-40 mph. The high winds will cause much blowing and drifting of the newly fallen snow creating very hazardous conditions that could result in near blizzard conditions in open areas.

 The sunshine with which Monday afternoon has opened belies the area's meteorological fate in coming days. The Chicago area sits at the precipice of a major snow event which may prove the heaviest and lengthiest of the 2009-10 season. To date, the 7.5" which fell Jan 6-8 tops this season's snowfall charts. The system which looms appears capable of producing 8 to 14" accumulations, heaviest in counties adjoining Lake Michigan from northeast Illinois into southeast Wisconsin and northwest Indiana, in what could be a 35 to 40 hour snowfall. A snowfall of nearly a foot would be the heaviest here in over a year, according to our climate guru Frank Wachowski.  A 35-40 hour stretch is a VERY LENGTHY period of snowfall by Chicago standards which could impact 2 and possibly 3 rush hours Tuesday into Wednesday morning!
    We understand a great deal more about snowflake formation than we once did--and this understanding is crucial when it comes to making accumulation forecasts. Here's why. Because the condensation nucleii--the tiny particles which float in the air around which snowflakes form are primarily composed of clay in this region of the world--this makes it critical for there to be to layer  of air with a temperature of-12 to -14-degree C or colder in order to initiate snow crystal formation around the clay nucleii which predominate in the Midwest. (Were these particles composed of substances other than clay, that would change the temps required to form crystals to something other -12 to -14 deg C). The deeper and colder that cold layer is in a storm, the more efficient snowflake formation is and the more "fluff" which occurs in the snowflakes which form.  This storm will have a comparatively DEEP cold layer--so fluffier snowflakes seem a good bet.
    One of the truly useful tools forecasters today have available are computer model estimates, based on analysis of the depth and temperature of the layer of cold air in snow situations as well as the predicted winds (strong winds can limit snowflake size by bumping flakes together and crushing the crystals at the edge of flakes), of what's called the "snow-water" ratio--in other words, a calculation of how much snow is likely to develop from the water a storm is expected to take out of the atmosphere.
     The incoming storm is predicted to produce a 16.3 to 1 snow/water ratio. (The typical storm here produces ratios closer to 10 to 12 to 1.) That means that given the size of snowflakes predicted in this storm, 16.3" of snow would result from an inch of water. A suite of computer models storm suggest the storm which hits in coming days will generate 0.45" to 0.80" of water. Using the 16.3 to 1 snow/water ratio, this suggests 8 to 14" of snow may occur by Wednesday morning. The winds forecast with this storm will be modest Monday night but will increase markedly Tuesday and Tuesday night. Gusts to 25 to 35 mph are not out of the question later Tuesday night and Wednesday morning--more than enough to encourage blowing and drifting.
    We expect snow to overspread the area this evening and to be falling steadily areawide by midnight--then to continue heavy at times Tuesday and much of Tuesday night. Lake effect snow could spill over into Wednesday morning and presents one of the wildcards of this storm situation-namely, how much lake moisture is to be entrained in this storm. The presence of lake moisture in the snowfall equation with the new storm makes it most likely the heaviest snow totals by the time the storm winds down Wednesday morning are to occur in lakeside counties from Kenosha County WI south to Lake and Cook Counties Illinois into Lake, Porter and La Porte Counties IN.
    We plan to keep the updates coming here at wgntv.com on our Severe Weather Blog as well as on our reports over WGN TV and radio.  Stay safe and thanks for checking out our blog!

Tom Skilling
   
   

A large portion of the Chicago area will be under a Winter Storm Warning starting tonight.  For the very latest on the developing storm and a complete breakdown of which Chicago area communities are included in the warning, follow the link below to the WGN Severe Weather Blog.

http://weblogs.wgntv.com/chicago-weather/severe-weather/

We already are more than 10" above average on snowfall to date this winter.  We only need about six more to bring our total to 38".  That would match the average amount of snow we get in an entire winter.  That shouldn't be hard to do with the prolonged, steady snow that will begin late tonight and last through Tuesday night.  More than two dozen states have advisories, watches or warnings.  Washington DC is bracing for more snow but not as much as the most recent storm. 

This could end up being one of the biggest snow storms of the year as we are expecting  anywhere from 6 inches to a foot of new snow. 

In addition to the updates on CLTV and WGN Radio, you can follow the storm through my facebook updates at

www.facebook.com/TimMcGillWeatherGuy

 

or check out my twitter updates on

 

http://twitter.com/WGNWeatherGuy

 

A steady light snow is expected to spread into the Chicago metro area Monday afternoon and begin to accumulate later that night. There will be an extended 24- to 30-hour period of snow as low pressure passes to the south and tracks east. Winds will grow much stronger Tuesday, gusting in excess of 30 mph gradually shifting from the east to the north by evening. Snowfall will be enhanced by the northeasterly flow off Lake Michigan. Going into evening rush hour Tuesday, snow totals could range from 6 to 10 inches with more to come. As the storm center pulls away into Ohio, snow and winds will slowly diminish Tuesday night, but north to northwest flow will result in accumulating snows around the south end of the lake and in northwest Indiana into Wednesday.

Mid-Atlantic in storm's sights

Another low pressure center will be tracking through the south in concert with the low moving through the Ohio Valley, spreading rain over the Gulf coast states. The southern low is expected to swing northeast, moving off the North Carolina coast Wednesday, pulling moist northeast flow and additional snow back into the same Virginia, Maryland, Delaware, New Jersey area hit with one to two-foot snows last Saturday.

Dear Tom,
You've noted more than once that large raindrops fall faster than small ones. What circumstances cause this apparent contradiction to what Galileo learned, namely objects of different weights fall at the same speed?
-- Dennis McGann, New Lenox

Dear Dennis,

At the Leaning Tower of Pisa, Galileo Galilei (1564-1642) demonstrated that bodies of different weights fall with the same velocities, but due to air resistance, objects such as feathers, with little weight for their surface area, will fall slower than dense objects, such as bricks. In a vacuum, all objects fall at the same rate: Feathers, bricks, hailstones, even misty raindrops.

The great Italian astronomer and mathematician, invented the telescope, but his greatest contribution to the advancement of knowledge was that his work helped establish mechanics as a science.

The weekend will end on a quiet note, but trouble is brewing for early next week.  For the very latest, follow the link below to the WGN Severe Weather Blog

http://weblogs.wgntv.com/chicago-weather/severe-weather/

These incredible pictures of the mega-snowstorm that buried the Washington D.C. area with more than 30 inches of snow in some areas were sent to us by  native Chicagoan Robert Schwartz a student at American University in Washington. The official snowfall at American University was 27.5 inches.

T

Photos by Robert Schwartz

As low pressure moved out to sea Saturday, the mid-Atlantic states of Virginia, Delaware, Maryland, New Jersey and Pennsylvania were digging out of record snowfalls. Totals in the Washington,D.C. area ranged from a low of 17.9 inches at Ronald Reagan National Airport to 40 inches in the northern suburb of Colesville, MD. Dulles Airport reported a record 32.4 inches. Philadelphia measured 28.5 inches with just over two feet in downtown Baltimore. Atlantic City had 18 inches while New York City received just a trace of snow in Central Park. Even locations in western Virginia and Maryland and eastern Pennsylvania had 1 to 2 feet.

Chicago in path of next storm

A storm is forecast to move out of the central plains and merge with a strong upper air disturbance coming in from the northwest Monday. Snow is expected to spread into the Chicago metro area Monday night and increase in intensity Tuesday. At this stage it's still too early to determine the exact track the center of the storm will take, but if preliminary guidance proves correct, northeast Illinois as well as southeastern Wisconsin and northwest Indiana are in for significant snow accumulations. Strong easterly winds would causing considerable blowing and drifting snow making travel extremely dangerous.

 

Dear Tom,
My father used to say "winter's back is broken" once we get into February. What do the statistics actually say?
-David Means

Dear David,
Chicago's weather records make an unequivocal statement that, on average, winter is not as harsh in February as it is in January, and data support your father's claim that "winter's back is broken" by Feb. 1.

February temperatures average 5.0 degrees higher than in January (27.0 degrees versus 22.0) and its snowfall is 2.1 inches less (8.5 inches versus 10.6), but the operative word is average. We live in a climate more prone to large swings above and below the averages than adherence to those averages.

In fact, despite the averages, February has been colder than January in 48 years out of 139 (35 percent), and snowier than January in 58 years out of 125 (46 percent).

Thanks to Julie Frey Wilke for sending us this neat picture of an unusual snow drift photographed about a mile off of exit 201 on I-65 near Remington, Indiana.

The Mid-Atlantic continues in the grip of a crippling snowstorm as Saturday dawns. Snow is predicted to continue falling heavily into early Saturday afternoon amid howling northeast winds from Washington D.C. north to Baltimore, Philadelphia and Atlantic City. Final tallies are likely to exceed 20"--and may well top 30" in mountainous areas of Virginia, Maryland and southern Pennsylvania to the west of the Nation's Capital--more than in the pre-Christmas storm which clobbered the area.

The storm, which on Friday generated snow over a 1,000-mile swath extending from Missouri to the Maryland and New Jersey coasts, threatens to generate record-breaking snowfalls which may challenge some of the region's long-standing winter benchmarks.

More than 10" of snow had fallen in the Nation's Capital late Friday evening, and heavy snow continued falling nearly horizontally there in roaring 32 mph winds--slashing visibilities to near white-out levels. Dulles International Airport, situated outside Washington in northern Virginia, reported 1/16 of a mile visibility in heavy snow late Friday evening while visibilities at Reagan-Washington National Airport were down to a quarter mile. Frostburg in the Maryland mountains reported 15" of snow on the ground late Friday evening with thunder snow in progress, while 17.5" had fallen at Headsville, W.V., in the northeast corner of the state near the Maryland border.

Rapid intensification of the storm is predicted to generate 50-plus mph wind gusts and full blizzard conditions on the coast and in areas close-by including Atlantic City Saturday before the storm finally moves out to sea late in the day.
    
Storm snowfalls may challenge all time Washington & Baltimore benchmarks for the most snow
 
In Chicago, the benchmark winter storm was the Blizzard of '67 which crippled the city with a 23" accumulation delivered on roaring 50 mph gusts. But in Washington, the snow-producer of record is the Knickerbocker Storm of Jan. 27-28, 1922.  That storm bears the name of the theater which suffered a deadly roof collapse when 28" of snow fell. The collapse killed 98 and injured 133.

Forecasters warned late Friday that the current system could produce accumulations in sections of the Washington area approaching such levels. Predicted totals of more than 20" from this storm in Baltimore could end up challenging the 28.3" record tally recorded there in the President's Day Storm of Feb. 15-18, 2003.
 
Modest snow Chicago area snow totals Friday
 
Snowfall Friday in Chicago was far less impressive, reaching an inch at a few mainly south suburban locations in the afternoon.  Lansing topped the accumulation list with 1.4" of snow while 1.2" fell at Willowbrook and 1.1" came down at Richton Park. In the city, an inch fell at Midway Airport, but amounts tapered to just 0.2" at O'Hare. West suburban Oak Brook and Downers Grove saw just 0.5".

Sporadic lake-effect flurries are to ride gusty north to northeast winds into sections of the metro area Saturday, but any accumulations are expected to be modest.

Monday night/Tuesday system bears some resemblance to Jan. 7-8's snowstorm here
 
A significant Chicago snowfall remains a risk Monday night and Tuesday. Much can change in two days--but computer models late Friday continued to indicate a southeast-bound speed max in the jet stream is to sweep from the Dakotas later this weekend into central Illinois Tuesday--potentially placing Chicago in an area of strong atmospheric "lift" Monday night into Tuesday. That's a set-up notorious for snow production.

Dear Tom,
I remember a 70-degree January day as if it were yesterday. Was it in 1987 or 1989?
--Cathy Disch

Dear Cathy,
It was Jan. 31, 1989, and though it was a sunny, windy and unseasonably warm day in Chicago, it did not reach 70 degrees. The city's official high that day was a record 65 degrees, which fell 2 degrees short of January's record high of 67 degrees, reached on Jan. 25, 1950. For the record, January is the only month in which Chicago has never recorded a 70-degree temperature.

The warmth of that January day in 1989 was short-lived and literally was the "warm before the storm." Temperatures crashed as February opened and a snowstorm followed, dropping nearly 7 inches of snow on the city by Feb. 5. On Feb. 6 the mercury plunged to 4 below zero over the fresh snow cover.

I don't think they make Hallmark cards for it but today is National Weatherperson's Day.  No joke.  It commemorates the birthday of John Jeffries back in 1745.  He was a Boston doctor and one of America's first weather observers. 

I wanted to use this event as an opportunity to thank those in my profession that have encouraged or inspired me over the years.  "The years" now span 25 or so.  I have been a broadcast meteorologist since 1985. 

I first want to thank my NIU professors, Dr. Reitan and Dr. Staver for making learning about meteorology fun and challenging.  I need to also recognize Harry Volkman's influence on my career.  He visited my class in grade school and made a huge impression on me.  Over the years I have come to know him personally and look up to him as a role model.  He is a smart, classy, funny guy and I value his friendship. 

It is hard for me to believe sometimes that right across the other side of my office is Tom Skilling.  What you see is what you get with Tom, a brilliant, passionate meteorologist who amazes me every time I talk to him about weather.  He is the real deal. I enjoy watching him as much today as I did thirty years ago.

Last but not least, there is Paul Konrad.  I have known Paul since the launch of CLTV back in 1993.  Paul has taught me everything I know about internet gambling.

Enjoy the snow and have a Happy National Weatherperson's Day!

The latest storm in what already has been an incredibly active winter season out East is headed for the major cities of the Mid Atlantic--including Washington, Baltimore, Philadelphia and possibly at least sections of the New York metropolitan area later Friday--while threatening Chicago with a period of snow and a weekend of chilly, lake-driven snow showers. The mammoth system is only to graze the Chicago area--reserving its fiercest blow for the mid-Atlantic where blizzard conditions are likely to evolve, driven by 40 mph gusts. Coastal areas such as Atlantic City, may well see white-out conditions brought on by  winds as high as 50+ mph. 

While a bit of drizzle or freezing drizzle possibly mixed with some ice pellets or a few flakes of snow flirt with Chicago Friday morning, a steadier period of snow is slated to arrive here later this afternoon and Friday night. An inch or more of snow has fallen on only 3 calendar days since Jan. 1. The incoming snow could lay down 1-3 inches of snow over sections of the Chicago area, becomingthe 4th one-inch-plus snow event of 2010.

Snow is predicted to be falling vigorously by mid and late afternoon Friday in Washington D.C.  That city already has a 2009-10 seasonal snow tally of 31.1 inches-- three times the normal of 12.4 inches to date. Remarkably, only 2 inches had fallen there by this time a year ago. The current season's snowfall---even in advance of the incoming storm---amounts to more than ALL the snow recorded across the District in the last 3 seasons combined.

As much as 16 to 24 inches of snow is predicted to fall there in the latest storm amid howling winds---and a foot or more of snow appears a good bet in Baltimore and Philadelphia as well. Effects of the storm are likely to be felt in those cities well into Saturday---though the heaviest falling snow is to begin winding down midday tomorrow.
    
 
Gusty, cold weekend winds to activate the lake snow machine
 
The storm's impact on Chicago's weather is expected to be far less radical. But the process of intensification---known as "cyclogenesis"--- will encourage air to rush into the system from its periphery, a set-up which is to manifest itself in the strengthening east to northeast winds likely to race through Chicago Friday. Gusts to 30 mph are possible by and during Friday night.

Lake-effect snow showers hit Saturday/Saturday night

Winds will blow from a northeast direction Friday night into morning then  become more northerly. It's a change which will increase the distance cold air travels over lake waters before reaching Chicago Saturday, raising the possibility initially light and scattered bursts of lake-effect flurries in the morning may increase to better-organized snow showers later in the day into Saturday afternoon and night.

Potent system bearing some similarities to the early January snow-maker here being monitored next week
 
A second, potentially more significant snow-maker may threaten the Chicago area area Monday night into Tuesday. The southeast-bound disturbance, predicted to dive from Manitoba Canada into Missouri Monday then track across Illinois. It's a development which could put Chicago in a strong region of "atmospheric lift" Tuesday setting the stage for snow.

 

Dear Tom,
January and February are the two coldest months in Chicago. Which months are in third place, fourth, fifth, etc.?
-Bill Philips

Dear Bill,
Here are the months and their average temperatures, ranked from coldest to warmest: January, 24.3 degrees; February, 27.9; December, 28.9; March, 37.7; November, 40.8; April, 49.6; October, 54.5; May, 60.3; September, 66.1; June, 70.5; August, 73.7; and July, 75.2.
We used Midway Airport data from 1929 to 2009 to generate those averages. Although monthly average temperatures are slightly different at other locations in metropolitan Chicago, the ranked order remains the same.

The ranking by season is winter (December through February), 27.0 degrees; spring (March through May), 49.2; autumn (September through November), 53.8; summer (June through August), 73.2. The first half of the year (January through June) averages 45.1degrees and the second half (July through December), 56.6.

How are things in your part of the troposphere?  The troposphere is the lowest layer of the atmosphere where we live and most weather occurs.  Scientists are now finding El Nino's influence on our weather isn't just limited to the troposphere but also effects the stratosphere.  

El Nino, the warming of the eastern Pacific ocean near the equator, has far reaching effects on global weather patterns.  We have seen those effects this winter with heavier than normal precipitation in the south.  Yet another storm will swipe the southern plains with snow today and tomorrow before deepening over the mid-Atlantic where numerous winter storm watches and warnings are posted.  Nearly a foot of snow could fall on the Nation's Capitol where they have already seen more than twice the normal snowfall this winter.

www.facebook.com/TimMcGillWeatherGuy

 

http://twitter.com/WGNWeatherGuy

If all the atmospheric chips fall into place in just the right way over the next week, the Chicago metro area could rack up snow tallies larger than the 4.5 inches of snow which fell all of last February. But the onset of snow isn't likely to occur until Friday--comparatively mild air is in the cards first. Thursday afternoon may host Chicago's mildest official high of the past 11 days.

Readings Wednesday hit  33-degrees at Midway Airport, 35 at the lakefront and 32 at O'Hare. The 36-degree official reading predicted for O'Hare Thursday afternoon would be the area's mildest since a 46-degree high on Jan. 24--nearly two weeks ago.

All is far from sanguine in the world of U.S. weather. A major storm is again under development--this time in the southern Plains. It's the first of two expected to come together in the next 7 days. The latest system has prompted the issuance of an array of winter storm watches and advisories across sections of 23 states--extending from New Mexico and the Texas Panhandle all the way to the East Coast near Washington, D.C.  The developing system is behind a series of gully-washing (and thundery) downpours which drenched south Texas Wednesday. Fredericksburg --northwest of San Antonio--measured 2.64 inches of rain while San Antonio proper logged a 2.50 inches daytime tally. Big snows on the storm's cold northwest side buried the mountains of New Mexico near Albuquerque with as much 8 inches of  snow.

The storm is to move from Gulf Coast waters east of Texas northeastward toward the South Carolina coast. It arrives there Friday afternoon then explosively deepens once in contact with western Atlantic waters east of North Carolina. It's at that point snowfall and winds should begin increasing rapidly across sections of the mid-Atlantic---including Washington, Baltimore and Philadelphia.

With the 2009-10 snow tally in Washington, D.C. now up to 31.1 inches---nearly 16 times the 2 inches which had fallen by this time a year ago and more than ALL the snow which has fallen there the past three seasons combined--another major winter storm is not what  East Coast residents need. The books closed on the region's last storm only earlier this week.

Providing the storm remains on the track now projected for it, a foot of snow could fall on the Nation's Capitol by Saturday. The strong winds on its north side are likely to buffet Chicago as well, strengthening slowly Friday and gusting to 30 mph at times Friday night and Saturday.

Estimates of how much snow the southern storm may produce here between Friday afternoon and Saturday night range on various computer models from 2 to as much as 5 inches--with possible lake-enhancement. These are preliminary figures which will be updated. Precipitation here may begin late Thursday night as a bit of drizzle, freezing drizzle, sleet or flurries likely to increase in intensity Friday afternoon and evening.
 
Rare mid-winter Air Pollution Action Day declared by Illinois EPA
 
It's not often an Air Pollution Action Day is declared in winter--but it happened Wednesday and extends through Thursday. A pollutant-trapping temperature inversion above Chicago, which in combination with light winds, has shut down the mixing of air which typically thins pollution concentrations, continues in place. Stronger winds will begin taking hold as the latest storms passes to the south bringing the pollution episode to an end.


 

Dear Tom,
I remember a huge spring snowstorm in the middle 1970s when it took me 8-1/2 hours to make a usually one hour trip home from work. Details please?
-John Dailey, Fort Smith, Arkansas

Dear John,
You and thousands of other Chicagoans were stuck in one of the worst spring snowstorms in the city's history. Following a night of rain and sleet, the precipitation changed to heavy wet snow during the day on April 2, 1975. The storm dropped 9.8 inches of snow and was accompanied by northeast winds gusting as high as 40 mph. The snow quickly clogged expressways, creating gridlock and forcing motorists to abandon their cars. The area was plagued by power outages and the storm forced O'Hare International Airport to close. Eight fatalities were attributed to the storm, most of them from heart attacks brought on by shoveling.

It's been quite a winter in Oklahoma. The latest ice and snow storm to hit that region produced the scenes you see here in just the past week---scenes photographically captured by Tim Koska and forwarded to us by our hard-working former intern Eric Szos, who now works as a meteorologist for Cherry Logistics Corporation in North Aurora. So bad was the icing in Oklahoma during the storm that law enforcement officials reported 200 or more power poles snapped in some locations producing power outages. MANY THANKS ERIC for sharing these with us---and please extend out thanks to Tim Koska for some amazing photos!
 
Tom Skilling
 






Photos courtesy of Tim Koska and forwarded to us by Eric Szos

It's been nearly a month since the Chicago area has been blanketed by a fresh layer of snow as heavy as Tuesday's. The 1.7 inches which fell at O'Hare was the heaviest since an early January snowstorm buried the metro area under 7.4 inches of snow--the season's heaviest to date. Though snow accumulated from one corner of the Chicago area to another, its was the west and north suburbs which registered the heaviest totals. Accumulations of 2.5 inches hit Arlington Heights and St. Charles while Oak Brook and Lake Bluff registered 2.1 inches. The snow fell in a quiet wind environment and with temperatures which hovered near or just above freezing at many locations.  This spared motorists on the area's major thoroughfares serious travels problems since road chemicals were able to work at maximum efficiency. Seasonal snow tallies surged to 31.9 inches Tuesday---well above the average of 22.4 inches to date--but just over a foot (12.1 inches) behind the same period a year ago.

Some sunshine breaks from the clouds Wednesday--and a southerly wind Thursday is likely to push temperatures above freezing for the first time in 11 days.  But, the break in snowfall may be temporary.  At least two systems capable of new snowfall loom in the coming week and are being monitored. The first is due Friday afternoon and evening and may, with the arrival of lake effect snows late Friday night and Saturday, extend into the first half of the weekend. Early computer estimates suggest significant accumulations are a good bet. Models run by the U.S. Navy and Environmental Canada put possible snowfall at 3 to 5 inches.  Moderately colder air follows the windy disturbance into the area Saturday night and Sunday.

A possibly more potent system sweeps southeastward from Canada on Monday into Tuesday.  Even colder arctic air may follow.

A winter like none recently in the Nation's Capital; District hit by new snow and another due late week
 
Washington, D.C., has already received more than 2 feet of snow this winter and another snowstorm is possible there this weekend. In stark contrast, at this point last winter, snowfall there totaled only 1.9 inches.

Dear Tom,
In September or October 1959 we heard the classic a freight-train wind sound for nearly a minute in the Edison Park-Norwood Park area on Chicago's Northwest Side. Trees were down all over the place. Was it a tornado?
Bob Johnson, Buffalo Grove

Dear Bob,
Around 7p.m. Saturday, Sept. 26, 1959, a tornado carved a 12-mile path of destruction from near O'Hare International Airport through Niles and Park Ridge. Most of the damage was F1 but there were pockets of F2 damage. The twister was spawned by severe thunderstorms that packed wind gusts to 75 mph. A garage was demolished near Touhy and Caldwell avenues and a roof was torn off a building at Milwaukee and Touhy avenues. Numerous boats were swamped on Lake Michigan and power failures were widespread. The Evanston and Wilmette areas were especially hard hit, with fallen trees blocking many streets. Storm damage was estimated at more than $250 thousand dollars.

Moderate to briefly heavy snow has been falling across portions of the Chicago area this morning.  How long will it last and how much snow will we end up with?  Follow the link below and check out the very latest on the WGN Severe Weather Blog (or just Google "WGN Severe Weather Blog").

http://weblogs.wgntv.com/chicago-weather/severe-weather/

 

 

 

I have a love/hate relationgship with Groundhog's Day.  I hate it but love it when it is over.  The best thing about Groundhog's Day is the movie of the same name it inspired that stars Chicago's very own Bill Murray.  Some local animal lovers oppose the holiday entirely and prefer to let sleeping groundhogs sleep.

Most studies show that Punxsutawney Phil is only about 40% accurate.  The good news (for most of us) is that the official long range forecast from the National Weather Service's Climate Prediction Center is for above average temperatures from February through April.  The forecast also calls for below average precipitation during that period.

There is at least one good use for groundhogs though, click here to find a recipe for groundhog and sweet potatoes.

Snow--modest by February standards---greets poll-bound area residents Tuesday. It's the first to fall in February and marks the 20th day this season measurable snowfall has occurred . It comes only days after the close of a January which tallied just 9.1 inches of snow, more than 80 percent of which (7.4 inches) which fell in a single early month storm on Jan. 7-8. The month's snow tally was 11.3 inches below the most recent thirty year average and more than a foot (12.4 inches) below January a year ago.

Tuesday's slushy Election Day accumulations are likely to range from 1 to a little over 2 inches--most of it accumulating on untreated outdoor surfaces, such a side streets, sidewalks and driveways. Absent Tuesday will be significant wind and bitterly cold arctic air, regular visitors in early February. Only 14 years ago in 1996, the city shivered through a bitter three-day cold spell during which a majority of hourly temperatures remained below zero setting new records--not only for the coldest Feb. 2 and 3 overnight lows on the books since 1871, but for the coldest daytime high temperatures as well.

Coming days will be nowhere near as cold  Daytime highs reach the 30s Tuesday and Wednesday and may make a move on 40-degrees away from Lake Michigan Thursday. These are temperature levels which assure road chemicals will work at maximum efficiency.

The sections of the metro area which receive 2 inch tallies Tuesday will have received nearly half the total amount recorded here ALL of February 2009. The month logged measurable snowfall on only four days. 

Snows end as sunshine emerges Wednesday. But a second system approaches Thursday bringing clouds back into the area even as southeast winds tap milder air and push readings in the sections of the Chicago area away from Lake Michigan to near 40-degrees. However, the warming will be short-lived. Winds between a strong Canadian high pressure to the north and a developing storm to the south will increase Thursday and Friday. The gusty flow it is expected to tap the reservoir of arctic air covering much of Canada and the far northern tier of the U.S., tugging the frigid air southward into the nation's Heartland over the weekend and into early next week.
   
Miami area hit with Monday downpours; totals top 8 inches in spots
 
As the clean-up continued Monday in the wake of gargantuan weekend snows from New Mexico to Virginia and the Carolinas, thunderstorms drenched south Florida Monday, hitting an area from Ft. Lauderdale and Hollywood to Miami and Homestead especially hard. Flood warnings were hoisted after 8.13 inches drenched Cooper City, 7.61 inches Pembroke Pines and 7.38 inches at Ft. Lauderdale. The rains flooded area thoroughfares.

Dear Tom,
We were in Los Angeles in mid-January during their very rainy weather and there were some thunderstorms as well. The residents said thunderstorms never occurred there, which I question. Is it true that Los Angeles almost never has thunderstorms? Is there any place in the world where thunderstorms never occur?
-Ruth Malik

Dear Ruth,
By Chicago's standards, thunderstorms in Los Angeles are relatively infrequent, but they do occur there and the claim of no thunderstorms is incorrect. Chicagoans can expect 38 days per year with thunderstorms; in Los Angeles, it's just five days.

Thunderstorms occur in practically every place on Earth at one time or another, but they are rare in some locations such as the interior portions of the Sahara Desert and the central Arctic Ocean. Only one place never has thunderstorms: interior Antarctica.

Our meteorological colleague here at WGN Richard Koeneman, who lives high in the mountains of western North Carolina at Fairview (near Asheville) sends us these incredible snow shots in the wake of the mammoth weekend snow there. Fantastic shots, Richard--THANKS for getting them to us!
 
Tom Skilling

Kristi Ikemire sends us these beautiful shots taken by her father-in-law Chuck Stone who lives in Kimberling City outside of Branson, Missouri. Kristi tells us:

"They don't see snow too much down there - so this was a big one for them."

True indeed! Thanks to you and Chuck for making these beautiful photos
available to us, Kristi! 

Tom Skilling