December 2006 Archives

The subject of global warming, bubbling in the meteorological community (and elsewhere in academia) for several years, finally burst controversially into the public consciousness in 2006. It’s our prediction that it will be an increasingly controversial topic in 2007.
The Earth’s climate is changing; indeed, all evidence is that it has always done so and always will do so, but a new (and controversial) factor in the “change equation” is man’s role in future climatic shifts.
We have been proceeding headlong and, until now, blindly into a future of “climatic uncertainty” in the sense that there exists an unknown ratio between the benefits and costs of climate change. Decision makers need to weigh and compare the risks of premature or unnecessary actions with the risks of failing to take actions that subsequently prove to be warranted. The issues are complex, but man has finally begun to address them.
--By Richard Koeneman, WGN Weather Center Meteorologist

This evening’s Bears-Packers game and other Chicago area New Year’s Eve celebrations will take place under cloudy and rainy skies, but with mild temperatures.
Afternoon readings climb to a relatively balmy 50º, a level reached in Chicago on only nine New Year’s Eves since 1870.
Midnight revelers will experience temperatures in the lower or middle 40s along with rain and fog. That stands is sharp contrast to a crystal-clear atmosphere that prevailed across the city on Dec. 31, 1967, when the thermometer hovered at -9º at the stroke of midnight—the lowest temperature ever registered in the city at the very moment the clock clicked into the new year. Somewhat colder temperature return to the area on Monday, along with a little snow, but the prevailing mild pattern that begin in early December persists. Rain and readings near 50º arrive again later in the week.
--By Richard Koeneman, WGN Weather Center Meteorologist

Another powerful winter weather system has descended upon the nation’s midsection, and this one is huge. Its cloud shield today extends from Arizona east to the Carolinas and from Mexico’s Yucatan Peninsula and the Gulf of Mexico north to Lake Superior and Ontario Province, Canada.
Precipitation associated with the system is falling from northwest Mexico to Minnesota, and the precipitation ranges from severe thunderstorms in the lower Mississippi Valley and blizzard conditions in the Great Plains to rain, drizzle and fog in the Midwest.
Thunderstorms in Texas triggered at least 15 tornadoes Friday afternoon, and the threat of severe storms shifts east across Louisiana and Mississippi today.
Area temperatures surged into the 50s Friday—a level that history tells us will be achieved only about one day in 10 in late December. Mild air persists today, but clouds and chilly lake winds temper readings somewhat.
--By Richard Koeneman, WGN Weather Center Meteorologist

Thursday’s reading of 50º at Midway Airport marked the eighth day this month that Chicago’s afternoon temperature has reached 50º. That’s not a record (December 1998 registered 11 days at or above 50º), but it is nearly triple the number of such days (three) experienced in an average December.
Midway Airport weather historian Frank Wachowski reports that as of Dec. 28, the month’s average temperature came in at 35.6º, fully 6.7 degrees above normal and enough to qualify as the ninth-mildest December in 79 years of weather records at that site.
And mild temperatures are forecast to persist through the holiday weekend. As a powerful and slow-moving new storm system organizes over the nation’s midsection, Chicago and the Midwest will lie in the storm’s warm, moist half. That means rain for us, but another major snowstorm—the second in a week—for the central Plains (including Denver).
--By Richard Koeneman, WGN Weather Center Meteorologist

Chicago’s daytime temperatures are expected to hold in the 40s through the closing days of 2006, and that might not seem particularly mild—especially when gray skies, gusty winds and rain accompany those readings, but it’s a relative thing.
The city’s normal daily high temperatures hover in the lower 30s at this time of year, so readings in the 40s are relatively mild when compared to the climatological expectation. We have not had measurable snow (at least 0.1”) since the first of December (when 5.8” came down officially at O’Hare) and the city area might very well sail through the remainder of the month with no additional snow.
Chicago’s next major precipitation event will be in the form of rain, and plenty of it, beginning Saturday and continuing through Sunday (New Year’s Eve). Computer models indicate rain totals in excess of one inch through the holiday weekend. --By Richard Koeneman, WGN Weather Center Meteorologist

An F2 tornado with ripped through the Daytona Beach, Florida area early Christmas afternoon doing considerable damage. Hard hit was the airport at the Embry-Riddle Aeronautical Institute where former WGN weather intern Marty Eisses is a student. Marty is also a weather observer at the Daytona Beach Airport and was on duty when the tornado struck. Scared but safe, Marty was able to send us these dramatic pictures of some of the damage incurred at Embry-Riddle.

PHOTO COURTESY: Marty Eisses

Developing low pressure to the south and an approaching cold front from the northwest combine for a change to colder conditions on Monday and a chance of snow later in the day. As a prelude however, bolstered by southerly winds and sunny skies, today should mark Chicago’s warmest Christmas Eve in nearly 2 decades—the mercury last rose as high as 48° on Dec. 24 back in 1987. Winds will shift northerly Monday and gradually strengthen pulling colder air into the area which will entwine into the northern sector of a large low pressure system developing well to the south. The result will probably mean bare ground will greet Chicagoans Christmas morning, but as the low center moves northeast, there is a good chance that snow could develop here in the afternoon and continue at night giving a Christmassy “feel” to the holiday. In stark contrast the southeastern U.S. next couple days may see warm temperatures and severe thunderstorms.
--By Paul Dailey, WGN Weather Center Meteorologist

The three-day rain event which began Wednesday finally came to an end Friday after dousing the city with record rainfall. Storm totals that reached 1.70” at Midway and 1.58” at O’Hare included a new daily rainfall record for Dec. 22 of 0.90” at O’Hare. The heavy rainfall was a product of the same storm system that brought upwards of 4 feet of snow to western portions of the Denver area. That this storm would produce rain—not snow—here was pretty clear from the start, but in a colder environment and a more eastern storm track, Chicagoans would have been digging out from a major pre-Christmas snowstorm. As colder air feeds into this storm, heavy snow warnings have been posted for parts of northern Wisconsin and Upper Michigan where up to a foot of snow may fall.
A mild weekend is on tap for Chicago, but colder air arriving on Christmas along with an evolving storm system to our east may bring enough snow to whiten the ground here by Christmas night.
--By Paul Dailey, WGN Weather Center Meteorologist

Ex-Chicagoan Jeff Hickman sent this picture of their chocolate lab enjoying the thick snow that recently blanketed parts of Colorado. Thanks Jeff for the snapshot!

The center of the low pressure system that paralyzed the Denver area with 2-3 feet of snow and spawned flash flooding and tornadic storms in Louisiana will pass through northeast Illinois today.
Mild temperatures by late December standards (lower 50s) accompanied by similar dew points will result in a nearly saturated air mass over Chicago. This morning’s rush hour will be hampered by patches of dense fog along with drizzle and light rain.
Today will start off in the lower 50s, marking the 7th time readings have reached that level at Midway Airport this month. Only seven other years since 1928 have seen as many or more 50°-plus temperatures in the Dec. 1-22 period.
Starting later tonight, temperatures will begin a slow downward trend as northwesterly flow sets in. Weekend highs will still reach into the 40s, but Christmas Day will mark the beginning of an extended period where highs will run in the more normal 30s.
--By Paul Dailey, WGN Weather Center Meteorologist

Thursday marks the 20th consecutive day here without measurable snow-the longest early and mid-December snow-free period in 13 years. Only ten times since official snow records began here in 1885 have comparable December periods failed to see at least 0.1” of snow. The current 2006-07 snow season’s 6.5” tally at O’Hare—much of it from the Dec. 1 storm—is half the 12” which had fallen by this date a year ago.
Denver and the west central Plains sit at the other end of the snow spectrum Thursday. The nearly 30” down in parts of the Denver metro area by late Wednesday evening had been whipped into 6 foot drifts by whiteout-generating 40-50 m.p.h. gusts—and another foot of snow was predicted. Accumulations threatened to reach 40” in parts of the city-more snow than typically falls in an entire season here.

--By Tom Skilling, WGN-TV Chief Meteorologist

The temperature turnaround since December’s opening week has been remarkable. The metro area is in the midst of its mildest mid-December period in the 67 years since 1939—a major change from the chill which gripped the area in this month’s opening 8 days. That open was the 6th coldest for a December here since 1870. The 40.0° average temperature over the past week and a half is running 11.8° above the 136 year average. Only five December 10-20 periods have been milder. The period is running more than 20° warmer than the same period a year ago.
A mammoth snowstorm is underway Wednesday in the Plains. It’s a system which threatens to bury Denver beneath more than two feet of snow while producing a travel-crippling blizzard and whiteout conditions into the western Plains, including sections of Nebraska and Kansas. 12 states are under advisories.
--By Tom Skilling, WGN-TV Chief Meteorologist

It is with a heavy heart that I must relay the unfortunate news of the sudden and unexpected death of Dennis Haller, a valued member of the WGN weather team. Dennis passed away this weekend at his home in Washburn, Wisconsin, a small town in far northern Wisconsin near Bayfield.

Dennis joined the WGN weather team in 1998 after his retirement from the National Weather Service and was a frequent contributor to this weather blog and the Chicago Tribune weather page. Not only was Dennis an excellent forecaster and extremely passionate about the weather, but he also had a love and an in-depth knowledge of gardening and astronomy that he frequently incorporated into his weather page features.

He will be greatly missed. Funeral /memorial arrangements are pending.

--By Steve Kahn, WGN Weather Center Meteorologist

Chicago temperatures rose into the middle and upper 50s during the early morning hours Sunday just before a cold frontal passage. O’Hare topped out at 54º while Midway reported a high of 57º—the fifth time this month that readings there have eclipsed the 50º mark. Just to the west, the 50º high at Rockford early Sunday tied the record high for the date, last reached in 1977. However, the 50s here were cool compared to Sunday’s highs in the 60s and 70s to the south. Some of the new record highs set included Louisville (70º), Springfield, Mo. (68º), and Beaumont, Texas (79°).
Though the 50s are gone here, the week ahead will still be mild for the season with highs in the upper 30s and lower 40s running well above the normals, currently in the lower 30s.
A storm system will bring rain—not snow—to the city later this week, and it’s beginning to look like Chicago will miss having a White Christmas for the third straight year.
--By Steve Kahn, WGN Weather Center Meteorologist

Chicago’s recent stretch of mild 40s and 50s is now in the rear view mirror as a more seasonable air mass takes up residence. But with Christmas approaching and the winter solstice just days away, Chicagoans are well aware of just how brutal winter weather can be here this time of the year. Though this week’s high temperatures will be down 10-15º they will still be above seasonable normals(lower/middle 30s), not too bad at a time of year when the mercury has frequently ventured into subzero territory.
Saturday’s departing warmth sent temperatures soaring well above normal, sometimes to record levels, across portions of the Plains and Midwest. Some of the new records included 84º at Childress, Texas, 72º at Joplin, Mo. and a record-tying 61º at Lamoni, Iowa.
Heavy rain continues in south Florida. West Palm Beach received more than 1.5” of rain Saturday elevating the total there since Thursday to around 10”.
--By Steve Kahn, WGN Weather Center Meteorologist

Saturday’s predicted 58° high—a reading 24 degrees above normal—becomes December’s mildest temperature to date and may well be the highest reading to occur in the final two weeks of 2006. Extensive high and mid-level cloudiness will filter sunshine during the day—otherwise, readings would be even warmer. The air mass in place here Saturday originated over 450 miles south of Chicago Friday over southern Missouri and Arkansas where 60s and low 70s were common.
The current mild spell has slashed December’s ranking as one of the city’s coldest. The opening eight days averaged just over 18°—6th coldest in the past 137 years. But the past week has boosted Chicago’s December average to 27.6°—the 40th coolest Dec. 1-15 period since 1870.
A 50° reading at Midway Saturday and Sunday would push to five the number of 50s this month. Only 13 other Decembers since 1928 have hosted as many or more 50s by Dec. 17.
--By Tom Skilling, WGN-TV Chief Meteorologist

These pictures were shot in Waukegan Township Thursday evening by Robbie Culver.

December nears its mid-point continuing to feel more like mid to late November. Sunshine will be plentiful Friday—something of a novelty in December, which is typically the area’s cloudiest month. To date, the month has logged 53% of its possible sun, well above the 39% considered normal. If that trend were to continue, December would become the first month in the past eight (since April) to receive more than its normal share of sun.
Thursday’s 53° high at Midway Airport was the second mildest Dec. 14 high since 1928. Only the 66° high on the date in 1975 was warmer. It marked the third 50° high this month at the South Side site—something that’s happened in December’s opening two weeks in only 17 other years. But, Saturday appears set to become the warmest day of the current mild cycle. A 60° would not only tie the record for the date set 22 years ago, it would mark only the 70th time in the past 137 years December has seen a 60°-plus reading.
--By Tom Skilling, WGN-TV Chief Meteorologist

Photos taken by Adam Ball on Thursday night (Dec. 14). Thanks Adam!
--WGN Weather Center Staff

Many thanks to Paul Havlik for this shot taken around 7 p.m. Thursday evening (Dec. 14) from Mundelein.
--By Tom Skilling, WGN-TV Chief Meteorologist

The aurora borealis are out tonight across a wide swath of the northern U.S.—including sections of the Chicago metropolitan area—in the wake of a giant solar flare which occurred 9 p.m. Tuesday evening, Dec. 12.

Astronomer Dan Joyce tells us the powerful X-Class flare is one of four which have occurred on the sun in the past week, sending the charged particles responsible for initiating this evening's multi-colored auroral displays streaming toward Earth. These charged particles excite oxygen and nitrogen in the atmosphere, creating the aurora borealis or northern lights. The auroral oval—a swath of the Northern Hemisphere most prone to northern lights—expands southward by a wide margin when strong solar flares initate what space scientists refer to as a geomagnetic storm, which can interrupt certain radio communications and interfere with satellite operation while at the same time prompting aurora displays. Reports in as of 7:40 p.m. Thursday evening indicate northern lights have already been spotted from North Dakota east to Pennsylvania, New York, Vermont and New Hampshire.

It’s most unusual for such strong solar flares to be occurring at this stage of the 11-year solar cycle, says Dan Joyce. We are just two months from the February minimum of the current cycle, a period in which solar flares—especially ones on the scale of the past four this week—are not what scientists expect to see.

Our thanks to Larry Spencer of Crest Hill for the above photograph of green-hued northern lights taken just after 7 p.m. Thursday evening, Dec. 14.

For more information on northern lights, here are some previous blog entries on the subject:
A Weather Kahnnections article by Steve Kahn

Archived photos: Article 1 | Article 2 | Article 3

--By Tom Skilling, WGN-TV Chief Meteorologist

Thursday’s mild temperatures, the first in a string of four straight highs above 50°, are better suited to late October than mid-December. Today’s 55° high is 20 degrees above normal and matches the normal highs here for Oct. 30 to Nov. 2. But as wonderful as this reading is, the best may come Saturday when the 1984 record high of 60° may be equalled if not exceeded.
Fast westerly jet stream-level winds are playing a big role in delivering the unusual warmth. While mountain ranges to the west wring most low-level moisture out of the atmosphere, mid and high-level moisture remains. Thursday’s trend to more cloudiness is evidence of that.
Three mammoth solar flares, the most recent Tuesday evening, forced astronauts into the International Space Station to escape potentially dangerous radiation for a time. Charged earthbound particles from these huge coronal mass ejections often set off auroral displays.
The Geminid meteor shower is visible again Thursday night. As many as 50-60 meteors an hour may be seen during such events.
--By Tom Skilling, WGN-TV Chief Meteorologist

December has historically hosted the third fewest 50° highs of any month. But, that didn’t stop the mercury Tuesday from peaking at 50° and 52° highs at O’Hare and Midway respectively, the area’s warmest readings in two weeks. As a signal the mild air isn’t done yet, Chicago’s predicted highs over the coming 7 days will average 20° milder than the daily highs observed the opening week of December, just the opposite of what might be expected.
Thunderstorms developed in southern counties of the metro area Tuesday afternoon with cloud tops above 40,000 ft. The first cloud-to-ground lightning stroke detected in northeast Illinois occurred around 4:07 p.m. well SW of Chicago in Livingston County. Storms spread northeastward in the two hours which followed generating as many as 40-50 lightning discharges per 15 minutes as they moved over sections of Kankakee and Will Counties and into northern Indiana.
--By Tom Skilling, WGN-TV Chief Meteorologist

Chicago’s mildest temperatures since the 60° high here nearly two weeks ago on Nov. 29 may lend support Tuesday to rare December thunderstorm development. Only one of the metro area’s 38 yearly t-storms occurs this month on average—just 3% of the city’s annual total. While it’s hardly a certainty all sections of the metro area will experience thundery downpours, odds for thunderstorms appear highest in the south and east suburbs. The day’s impressive vertical temperature decline—a situation meteorologists refer to as an “unstable” atmosphere—in combination with the arrival of a powerful pocket of upper level winds, supports the potential for t-storms similar to those in the Omaha, Nebraska area where 3/4” hail bombarded Falls City Monday. It’s been four years since December thunderstorms traversed the area on the 18th and 19th of this month in 2002.
--By Tom Skilling, WGN-TV Chief Meteorologist

In December’s first nine days, Chicago’s temperatures averaged nearly 12 degrees below normal, but the next seven days look to make up a good portion of that deficit. Readings for the Dec. 10-16 period are projected to average nearly 10 degrees above normal. Temperatures this week are expected to stay within a narrow range with extremes from the upper 20s to mid 40s as opposed to the wide swings (from near zero to the mid 30s) experienced Dec. 1-9. The still rather extensive snow cover—especially to the west and north—will continue to hold highs in the lower 40s at best, while in the city proper and to the south and southwest over bare ground, readings may be some 10 degrees or more higher. However, clouds, rain, fog and consistently mild temperatures will take a significant toll on the snow cover.
In the Pacific Northwest, an unrelenting series of storms continue to dump heavy rains along the coastline and heavy snow in the mountains.
--By Paul Dailey, WGN Weather Center Meteorologist

As the upper air pattern adjusts, with the jet stream flow over the Mississippi and Ohio valleys becoming more southwesterly, strong southerly surface winds will persist over northern Illinois into the middle of the week ahead. The resulting warming trend will see temperatures average some 8° above normal during the next seven days. These mild readings along with evaporation-enhancing gusty SW winds will combine with fog, light rain and drizzle tonight and Monday, and eventually a steady rain Tuesday, to gradually eliminate this area’s snow cover. Just a week ago, snow on the ground was extensive and over a foot deep in the western suburbs.
As the SW jet stream flow here strengthens, the West Coast will experience an enhanced NW flow aloft that will steer a series of northern Pacific frontal systems southeast, initially hitting the coastline with frequent periods of rain and then snow at higher mountain elevations inland.

--By Paul Dailey, WGN Weather Center Meteorologist

For Plains residents, subjected to bitter subzero temperatures only the day before, Friday’s surge into the 60s had to be stunning—the equivalent of moving from the dead of winter to spring in just two days. And, it offers Chicagoans an insight into the trend toward higher temperatures expected in coming days.
Temperature increases won’t be as impressive here. The presence of the Rockies just west of the Plains sets up compressional warming as air crashes down the mountain slopes. We lack mountains to the immediate west here in Chicago, so the degree of warming which can take place isn’t as eye-catching. But, the metro area is in for its most impressive warm-up in over a week and a multi-day thaw likely to obliterate the area’s snow cover.
The temperature increases over the past three days in the Plains have been dramatic. Valentine, Neb., recorded a -14° low Thursday morning but had a 66° high Friday—an 80-degree increase.
--By Tom Skilling, WGN-TV Chief Meteorologist

Thursday’s 17° high—the second such reading in just the past week and a reading 20 degrees below normal—would have been right at home in January, our coldest month. Since 1870, only 37 highs of 17° or lower have occurred so early in the season—on or before Dec. 7—in Chicago. That there has been not one—but two days this cold—puts the current cold weather anomaly in a league all its own. Only 11 years since 1870 have managed two 17° daytime highs by this point in a cold season here.
Subfreezing temps literally touched each of the Lower 48 states Thursday. Only sections of 8 states were free of readings below 32°. The chill spilled south to north Florida and the Gulf Coast overnight where a hard freeze was predicted.
December’s first 7 days have averaged just 19°—nearly 14 degrees below normal. That makes this the sixth coldest such period on the books. But, cold as it’s been this Dec. 1-7, the same period a year ago was 2.4 degrees colder!
--By Tom Skilling, WGN-TV Chief Meteorologist

Significant wind-driven lake-effect snows hit the snow belts of western Michigan and north-central Indiana Thursday. John Gehr of Holland, Mich., forwarded these shots from his neighborhood late Thursday and reports more than a foot fell in his area. National Weather Service co-op observers reported up to 21" in hardest-hit sections of Van Buren County, Mich. Wind gusts reached 48 m.p.h. earlier today at South Haven and Michigan City. Thanks John for the great snow shots!
--By Tom Skilling, WGN-TV Chief Meteorologist

Pilot Anson Mount, who flies out of Waukegan, snapped these shots of today's lake-effect clouds and snow bands while flying across the lake from Michigan. Check them out and read Anson's description of his photos:

Some snaps from this morning's crossing from Battle Creek to Waukegan at about 8,000 feet initially then down to 2,500 just offshore.

The first pic is approaching Kalamazoo; you can see the wedge shape to the cloud base as we approached the heavy snow bands.

The next is in the tops with ambient temps at 8,000 feet of minus 21 C ... the windows were frosted over!

The last is of the lake. You can see how the water is evaporating and can also see Chicago skyline in the distance.

Many thanks to Anson, who's a frequent and always reliable observer of our fascinating Midwest weather scene.
--By Tom Skilling, WGN-TV Chief Meteorologist

Our WGN-TV colleague Richard Koeneman and his dog Sadie take in the snow, which accumulated on Richard's back porch at the 3,650-foot level of North Carolina's mountains near Asheville. The same mammoth mass of frigid arctic air responsible for the Chicago area's bitter chill and healthy lake snows in sections Thursday across the lake snow belts of western Michigan/northern Indiana dropped porch air temperatures to 25 degrees at 5:15 p.m. Thursday evening.
--By Tom Skilling, WGN-TV Chief Meteorologist

Temperatures surged above freezing for 13 hours Wednesday in advance of the frigid air mass tightening its grip on the area. The break followed more than four days in arctic air. Wednesday opened with readings of 35° at O’Hare, and 37° at Midway . But, temperatures had dropped into the 20s by nightfall and were expected to tumble to single digit levels amid 30 m.p.h. wind gusts by Thursday.
A gargantuan and bitterly cold arctic high pressure system is to generate central pressures over the Plains close to Chicago’s record 1989 high of 30.98” while sending peak pressure readings here above 30.65”. A system this strong keeps wind velocities high and pumps frigid air into the area faster than the sun is able to warm it. This suggests readings may retreat to and hold in single digits over much of the area Thursday. Desperately low indoor humidities of 7% should encourage the use humidifiers to bring humidities closer to 30-35%.
--By Tom Skilling, WGN-TV Chief Meteorologist

Until late Tuesday evening, Chicagoans had shivered through 112 uninterrupted below-freezing hours. The sub-32° spell began last Friday morning at 5 a.m. It ended when the mercury reached 32° at 10 p.m. Monday evening at O’Hare and broke above freezing reaching 33° at Midway. Readings were expected to rise several additional degrees overnight and hold into the first hours of Wednesday. However, the area swings back into the firm grip of arctic-origin air Wednesday night. Daytime temperatures retreat from early low 30s, settling to 20° by nightfall then to single digits late Wednesday night.
Tuesday morning lows returned to sub-0° levels for a second straight night across Chicago’s western suburbs (i.e. Aurora -3°, Rockford -2° and -1° DeKalb) while readings at O’Hare bottomed out at 7°—the third consecutive single digit low there. Only four times in the past 106 years have three single digit lows occurred back to back this early.
--By Tom Skilling, WGN-TV Chief Meteorologist

National Weather Service COOP observer Chris Neaville shares these photos of last week's storm he took in the Mt. Pulaski area. Electricity still hasn't been restored to sections of the region.
-Tom Skilling

PHOTO COURTESY: Chris Neaville

Thought you might get a kick out of this from Marty Eisses in Daytona Beach, Florida. Marty interned with us in the WGN-TV/Tribune weather office several years ago as he completed his meteorological studies at NIU and has served as an official observer at Midway Airport and has worked closely with our Frank Wachowski there. Marty, who's currently involved in graduate meteorological studies at Embry Riddle Aeronautical University in Florida, tells us this is the way he conducted an early and tongue in cheek celebration of Christmas on Daytona Beach in Florida! He tells us this drew a good number of onlookers from the local hotels. Marty, a native Chicagoan, says he misses snow and is looking forward to his upcoming holiday break to check out our Chicago area snow. Thanks for your sense of humor and for sharing this with us Marty!

-Tom Skilling

Temperatures reach 32° here for the first time in over 4 days this afternoon in what has been the coldest December open since 1976. The first four days of the month have averaged 18.5°—a reading 13.8° below the 30-year norm and also cold enough to qualify among the ten coldest Dec. 1-4 periods since records began here 136 years ago in 1870.
Tuesday’s predicted 33° high, while chilly—particularly in light of the day’s gusty SW winds—actually marks an improvement over Sunday’s record breaking 15° high and Monday’s 26° reading. Only two days all last winter were colder than the 15° recorded Sunday. A reading that cold typically doesn’t occur here until Dec. 30.
More than a dozen cities across eight states recorded new record lows Monday morning including 0° downstate in Springfield and 22° at Dallas, Texas.

--By Tom Skilling, WGN-TV Chief Meteorologist

Glen Hubert, who provides us these photos of Friday's snowfall, reports Island Lake, Illinois received 12-15" of snow. Thanks for sharing these with us Glen!

-Tom Skilling

PHOTO COURTESY: Glen Hubert

Jeremy, Sarah and Caitlin share these shots of late last week's 12-14" snowfall in the Lake in the Hills area! Many thanks!

-Tom Skilling

Winter generates its own beauty as is evident in these photographs taken by Roberta Schommer in Lake Forest Saturday around 7 a.m. The area received 12" of snow. Thanks Linda for sharing these shots with us!

-Tom Skilling

PHOTO COURTESY: Roberta Schommer

More shots taken in the midst of last week's big Friday snowstorm courtesy J Kleeman. (Thanks Jay!). The chill in the storm's wake continues to grip the area. Not only was Sunday's 15-degree official
high at O'Hare a new record low max for December 3, it was Chicago's coldest daytime temperature since last February 18. Only two days ALL of last winter were any colder!

-Tom Skilling

Chicago’s early season cold snap became one for the record books Sunday when the official high at O’Hare Airport peaked at only 15º, eclipsing the day’s previous lowest maximum of 16° established 64 years ago in 1942. The cold weather arrived with a vengeance last Thursday after more than a week of highs in the 50s and 60s. In the midst of a major snowstorm, readings here dropped below freezing at 5 a.m. Friday morning and have not been above 32° since.
Chicago’s first shot at a thaw will not come until Tuesday afternoon, but if that does not materialize, readings above freezing may not occur until next weekend.
The cold weather has penetrated all the way to the Gulf Coast, where freeze watches and warnings are posted from southern Louisiana to northern Florida.
The cold spell is expected to ease here by the end of the week as a jet-stream realignment re-establishes the mild westerly Pacific flow that was so prevalent here during late November.
--By Steve Kahn, WGN Weather Center Meteorologist

Cold weather will remain well entrenched over Chicago this week with temperatures more typical of January than early December. Normal highs typically reach 40º, but this week readings will struggle to reach the freezing mark. The combination of cold days and morning lows near or below zero over snow covered areas, point to one of the coldest December openings in years. The same storm that brought heavy snow to portions of the Chicago area dropped up to 16 inches of snow in southeast Kansas, where the city of Chanute dropped to a record low of -2º Saturday.
While no new snowstorms loom on the immediate horizon, several disturbances passing through the Midwest promise to bring Chicago frequent periods of light snow or snow showers, while reinforcing the cold weather. Some warming is finally showing up on long-range computer models, but is not expected arrive until next weekend at the earliest.
--By Steve Kahn, WGN-TV Meteorologist

The final flakes of snow with Friday’s powerful Chicago area winter storm fluttered earthward just past 1 p.m. in the city. The 6.2” accumulation at O’Hare was the biggest early season snow here since 1978. But, it was the west and northwest suburbs—well away from Lake Michigan’s warmth—which bore the brunt of the powerful system that only six days earlier had roared off the Pacific into Oregon, beginning a 3,500-mile trek south to Texas and then north into the Midwest.
Northeast winds off Lake Michigan and a layer of warm air aloft switched what could have been hours of snow in the city proper into sleet/rain Thursday night, cutting accumulations to half what they might have been. But snowfall, enhanced beneath embedded 32,000-foot thunderstorms, offered areas north and west little break from snow which slashed visibilities below 1⁄4 mile. A 15.2” total at Libertyville and 12” at Arlington Heights were among the heaviest reported.
--By Tom Skilling, WGN-TV Chief Meteorologist

WINTER STORM UPDATE: 7:55 P.M FRIDAY

Storm wallops areas north and west of Chicago the hardest with 17" snow, drifts up to 4 feet—one of the area's earliest major snowstorms!

Never has so much snow fallen so early across Chicago's west and north suburbs. Storm accumulation reports into our weather office indicate as much as 17 inches at the Kenosha, Wis., Coast Guard Station, 15.2" at Libertyville, 15" at Streamwood and 13" at DeKalb. There were several unconfirmed reports of as much as 19-20" in areas nearby. Drifting has no doubt complicated snow measurement in some areas. A foot of snow was reported by my WGN/Tribune meteorological colleague and longtime National Weather Service forecaster Steve Kahn at Arlington Heights, and 12" was also reported in Mendota while 11" was reported to us in St. Charles by another of my WGN colleagues, Paul Dailey.

The official measurement at Rockford of 10.7" obliterated the old record for that city's greatest snowfall on this date, nearly doubling that site's previous 5.7" set 28 years ago on Dec. 1, 1978. Though falling snow has departed, wind gusts above 30 m.p.h. continue and drifts up to 4 feet high have been reported in the hard-hit area west and north of Chicago. The huge snow tallies dwarf the more moderate tallies observed in Chicago proper where sleet and freezing rain which fell much of the night through 5-6 a.m. this morning cut into storm totals. A layer of warm air aloft and strong, lake-warmed winds off Lake Michigan's 46° Lake Michigan waters, responsible for delaying heavy snow's thundery onset here around daybreak—a development noted as possible in our advisories over recent days—was overcome by the strong "lift" induced with the arrival a powerful band of jet stream winds referred to by meteorologists as a "jet streak." One function of the complex computer models forecasters employ in generating weather forecasts is to track the movement of these powerful pockets of wind aloft, in order to time the onset of vigorous upward air movement which led to the development of 30,000-foot thunderstorms embedded within this morning's storm. An e-mail I received from one of our Chicago viewers indicates the claps of thunder with these storms were so loud, car burglar alarms went off across his neighborhood.

Though not as heavy as the totals to the west, Midway Airport's 3.3" and O'Hare's official 6.2" qualify as the new snow season's heaviest totals to date, and produced a nightmarish morning rush hour for commuters and the hard working folks at Chicago Streets and Sanitation, who were forced to take on the wind-driven, visibility-slashing and occasionally lightning-laced snowfall in wind gusts clocked at one point at 44 m.p.h. Trees and most objects outdoors are snow-covered as this report is filed, lending the city a winter-wonderland type appearance. By contrast, most precipitation fell as rain with brief snows at the end across northern Indiana. At many locations there, only a dusting was reported. And far south suburban locations reported amounts of 1-2" or less.

The powerful storm arrived with quite a history behind it. Its cross-country trek produced 39" of snow near Alta, Utah; 17.8" at Genessee, Colo.; 16" Chanute, Kan.; 18" at Butler, Mo.; and a top snowfall of 15.2" in Illinois at Libertyville in Lake County. At one point Thursday evening, an 1,110 mile swath of the nation's Heartland was under one form or National Weather Service winter weather advisory or another as a result of the huge and powerful early season storm system.

Please check out the storm snow photos our readers and viewers have been kind enough to submit to us. We'll continue posting them for you as they arrive. We'll have complete coverage of the storm and its impact on our area on Friday evening's WGN Nine O'Clock News.

HERE'S A SAMPLING OF SNOW TOTALS IN TO US FROM OBSERVERS ACROSS THE AREA, INCLUDING A NUMBER OF NATIONAL WEATHER OBSERVERS:
NOTE: Several totals have been updated as of 7 p.m. Friday

Sources: National Weather Service co-op observers, WGN viewers

--By Tom Skilling, WGN-TV Chief Meteorologist

The following images were taken by WGN Weather Center graphic artist Thomas Valle Friday morning on the North Side of Chicago:

The following images were taken by Tina Henry in Grayslake, Ill.

In Remington, Ind., snow wasn't the issue on Friday—it was rain that caused flooding as seen in these pictures below from Mary Anne Best.

Finally, Sharon from Palatine sent this picture taken Friday afternoon from her balcony across the street from the Palatine train station. The planter boxes are 8" deep, which will give you an idea of the amount of snow that collected on her balcony!

Thanks to everyone who sent us their photos!

HEAVY SNOW IN ARLINGTON HEIGHTS

As of 10.25 a.m. this morning more than 11 inches of snow had accumulated in Arlington Heights . Light snow is still falling, but the storm is definitely winding down. Total snowfall here should top out at around 1 foot.

Steve Kahn WGN-TV/Chicago Tribune Meteorologist