November 2004 Archives

It was snowing—and snowing hard well west of Chicago as the sun set Tuesday. But, the late hour at which the snow finally reached the city spared evening rush hour commuters the mindnumbingly-long travel times in the pre-Thanksgiving snowstorm just under a week ago. That didn’t mean the city was completely spared. Up to 1-2” of snow was expected to greet early risers Wednesday who are to rise beneath sunny skies.

Snowfall had reached 6” late Tuesday evening at Ashton in Lee County, well to the west of Chicago. Other totals included 5.5” at Belvidere and Dixon, 4.8” Rockford and 4.2” near DeKalb. North suburban Lake Villa was hit by 2.4”. By contrast, through 10 p.m. the city and nearby locations measured snow in tenths of an inch—including 0.3” at Oakbrook and O’Hare and 0.1” at Midway.

Unusually chilly air gripped the West Tuesday. Highs of 47° at Las Vegas and 58° Palm Springs set records.

-Tom Skilling

I thought this might be of interest to the snow-lovers among you. Snow in Alaska--and lots of it. These pictures arrived from my friend and colleague Tom MacPhail in Alaska. Tom is a meteorologist who has lived in Alaska for decades and knows the state and its weather like the back of his hand. He is a passionate snow-enthusiast and has sent me these Thanksgiving holiday photos from the cabin he and his wife Kathy have in the breathtaking wilderness area two and a half hours drive (about 120 miles) north of Anchorage (also north of Talkeetna). The cabin is almost literally in the shadow of Mt. McKinley, North America's tallest mountain, and the towering peaks of Alaska Range.

The Alaska Winter weather program we produced and aired last winter included a segment in which my producer Pam Grimes, videographer Kevin Myers and yours truly spent several days at Tom's request at his cabin in the midst of last January's bitter cold there. I returned there with Tom this past
September with the leaves changing and in all of their autumn splendor. What an experience that was! Tom tells we're looking at a recent 12-14" snowfall which fell on top of the 3-4 feet already on the ground. Though there have been periods of rain and mild air farther south near Anchorage, snowfall this year has been abundant, as you can see!

Tom, who headed up the military weather operation for years at Alaska's Elmendorf Air Force Base and also served as one of the state's most popular television meteorologists on KTVA-TV, the CBS affiliate in Anchorage, is currently a Councilor of the American Meteorological Society and works as a forecaster, tracking Alaska's always challenging weather as a member of the Aviation Unit of the National Weather Service Forecast Office in Anchorage.

-Tom Skilling

Tuesday marks the last full day of meteorological autumn—a season which finishes among the mildest 30% September through November periods in 135 years of weather records. Since 1870, only 39 have been warmer. Milder than normal temperatures dominated the period, accounting for 70% of the daily readings recorded here. But, it’s November which, when compared to the long-term temperature average, has turned out warmest of the three autumn months. This month’s 44.2° average finishes nearly 4 degrees above the 40.5° observed here since the mid 19th century.
Texas continues a state with huge weather extremes. While McAllen on the Rio Grande River soared to 92° Monday—a a new record and far above the 75° considered normal this time of year—another 0.8” of snow fell to the north at Amarillo in that area’s latest autumn storm. That brings the Panhandle community’s monthly snow total to 13.8”. Never has a November there been snowier.

Veteran Chicago weather observer and historian Frank Wachowski was kind enough to supply these fabulous historic pictures of key staff members from Chicago's National Weather Service offices (back when the organization was known as the U.S. Weather Bureau):

IVAN W. BRUNK: Mr. Brunk was in charge of the Bureau's downtown Public Service Unit during the 1950s. The Public Service Unit served Chicago's media and TV stations. (Note: The Weather Service currently has no offices in downtown Chicago.)

JOHN J. SULLIVAN: Mr. Sullivan served as Chicago's climatologist from 1952 through 1972. He was stationed at the Federal Building in downtown Chicago, and was responsible for preparing the Bureau's monthly data forms, which included a narrative summary of the month's weather events (a feature missed in current-day weather summaries). Mr. Sullivan passed away in the early 1970s.

Special thanks goes to Frank Wachowski for supplying the pictures and information on their careers.
-- WGN Weather Center

A second taste of wet snow in a week is expected today and Tuesday for Chicago and northern Illinois, but a real challenge has been tossed to many residents of the southern Rockies and central Plains. On Sunday night, avalanche warnings were posted for much of the Colorado Rockies where 10 to 20 inches of new snow on top of a weak snow pack coupled with strong winds created unstable conditions. Nearly 150 avalanches had been reported as of Sunday evening, and travel had come to a crawl or stopped on many highways including Interstate 70. Interstate 80 was closed in western Nebraska, where a foot of snow and strong winds shut travel down completely.
After experiencing weather on the northern edge of this storm as it passes far to the south, Chicago will be in for a sunny day Wednesday before a sharp 24-hour cold spell begins later in the day Thursday and lasts through much of Friday.

Northern Illinois will be on the northern edge of a wintry weather mix early this week. The low pressure system that gave steady rain and totals of 0.50 to 0.75” Saturday has moved east.
Thanksgiving weekend travelers will depart Chicago under fair skies, but run into weather problems the farther they go as they head west, north and east. The rains just experienced here lie in wait for those headed east. Snows from that same low pressure system are diminishing, but continue to fall to the north, especially along the lee (downwind) shores of lakes Superior and Michigan. Heavy snow is expected today in the west-central Plains and central Rockies as a low pressure system pushes into the Southwest.

As that storm moves out of the Southwest its track will determine Illinois weather later Monday and Tuesday. Much of Illinois could be in store for rain with a wet snow or rain/snow mix across the north.

Rain—more than a half an inch of it—is to drench Chicago at times Saturday. Except for possible flurries Saturday night as colder air blows into the area, accumulating snows have shifted well north and west of the city. The 4.1” earlier this week has pushed the area’s seasonal tally to a level (4.1”) which hadn’t been reached here until Jan. 4 last cold season. It’s a total above the amount on the books by Nov. 27 in 96 of the past 120 years.
Nine states are under winter weather advisories this weekend, the closest of them: northern Wisconsin and Minnesota as well as Michigan’s Upper Peninsula.
In a holiday weekend which got off to a nightmarish start in Chicago area as a result of Wednesday’s snowstorm, there’s good weather news for homebound travelers planning to leave Sunday. Quiet weather is expected across much of the Midwest. The one region of the country with troubled weather will be the West, where a gathering storm threatens big mountain snows.

The 4.1" snowfall logged at O'Hare made Wednesday's storm the heaviest in November here in nearly 30 years! The city hasn't had a bigger snow in November since 7.5" fell on November 26, 1975.

-- Bill Snyder, WGN-TV weather producer

National Weather Service-Chicago snowfall analysis illustrates Lake
Michigan's impact on Wednesday's storm totals here

National Weather Service meteorologist Mark Ratzer has generated a fascinating post-storm Chicago area snowfall analysis which illustrates just how much of an effect Lake Michigan's warmth had on area snow accumulations this past Wednesday. Though evaporative cooling--a process which removes heat as precipitation falls into a dry air and initially evaporates--permitted snow to reach into the city, lakeside accumulations were far less than those to the west---in the Fox Valley, for instance.

Here is a link to the snowfall distribution map:
http://www.crh.noaa.gov/lot/science/24nov2004/snowmap.gif

Wednesday's wet snow produced beautiful scenes around the area. Included here are photos submitted to us by John J. Kleeman and taken in Chicago's northwest suburban area. The heavy, wet, wind-driven snow clung to trees and outdoor structures.

Wednesday's snow fell in the city with a 12:1 snow to water ratio--more than the usual 10:1 ratio. But, the snow was heavier west and north of the city--the "heart-attack" variety, so named because of the difficulty such snow presents to shovelers because of its weight--since rain changed to snow there earlier, allowing for more significant accumulations.

-- Tom Skilling, WGN-TV Meteorologist

With 4 inches of snow on the ground at 6:00 a.m. Thanksgiving morning, Chicago officially recorded its 10th White Thanksgiving (1 inch or more of snow on the ground) since snowfall and snow depth records began in Chicago 120 years ago in late 1884. This morning's 4" snow depth was the third greatest, surpassed only by the 8 inch snow depths recorded on Thanksgiving morning in 1895 and again in 1975.

Here is the complete list of Chicago's White Thanksgivings
Nov 28 1895 8” on the ground
Nov 26 1903 1”
Nov 27 1947 3”
Nov 24 1949 1”
Nov 23 1950 2”
Nov 27 1975 8”
Nov 23 1989 2”
Nov 28 1996 1”
Nov 28 2002 2”
Nov 25 2004 4"

A very Happy Thanksgiving to all!
Steve Kahn WGN-TV/Chicago Tribune Meteorologist

The freshly snow-covered Chicago area shimmered in Thanksgiving’s bright sun—a distinct change from Wednesday’s wind-driven snow. The final official tally on Chicago snowfall in the storm reached 4.1” at O’Hare. But the highly reflective snowpack, over which west suburban temperatures plummeted to single digits to the city’s west in the Sugar Grove/Aurora area (8°) Thursday morning for the first time this season, interfered with daytime warming which occurs so strongly over bare ground. The result was fall 2004’s coldest high temp and the chilliest reading here since 33° last March 21. The December-level reading meant that Thanksgiving 2004 ranked 35th coldest on record here since 1873. The chill’s plunge into the Deep South prompted frost and freeze warnings south to Mississippi and Alabama.
While Chicago’s has its first snow on the books, Madison, Wis.—where measurable snows usually hit by Nov. 5—has recorded only a few flakes to date.

Mary Anne Best was kind enough to share some pictures taken this morning in Remington, Ind., in the aftermath of last night's snowstorm. "I wanted to take more pics all day long as the sun shined on the snow and trees, making it more beautiful," she said. Thank you Mary Anne!
-- Tom Skilling and the WGN Weather Center Staff

Happy Thanksgiving to all! Thanks to a final burst of heavy snow over the city late Wednesday night, the final official snowfall tally at O'Hare reached 4.1". The storm was, as we explained on our Tribune weather page, a record breaker for Nov. 24 here in Chicago and had to overcome some real obstacles in doing what it did in the snowfall department--namely an extraordinarily warm lake (temps were near 50 degrees as the storm approached and Wednesday's powerful northeasterly surface winds were blowing in off that warm water).

It was the biggest single day November snowfall here in 27 years and produced a snow cover on Thanksgiving Day for only the 10th time since the snowfall records here began in 1885. My thanks, as always, to my colleagues Bill Snyder, Steve Kahn, Frank Wachowski and Richard Koeneman here at WGN for their work in their work pinning those stats down.

I want to call your attention to an excellent analysis of Wednesday's pre-Thanksgiving Day, 2004 storm put together by Bill Nelson, Mark Ratzer, Christine Krause and Al Pietrycha of the National Weather Service-Chicago. You can check it out by clicking on this link to the National Weather Service-Chicago home page:

http://www.crh.noaa.gov/lot/science/24nov2004/2004thanksgivingsnowstorm.html

We've been receiving some excellent photos of the results of Wednesday's snowstorm--the first in this area of the season--and plan to post some excellent photos shortly. Please check back with us on that...
-- Tom Skilling, WGN-TV Meteorologist

It’s been 27 years since a November day here has produced more snow than Wednesday’s slushy 3.1” total. The tally established a new record for Nov. 24, passing the 2.5” measured in 1947 and 1949. Although sunshine and warm ground temps are to go to work on the new snowpack Thursday, the windy storm has set the stage for only the tenth Thanksgiving on record here with snow on the ground since weather observations began in 1885.

Pre-Thanksgiving evening rush hours are always difficult. But, the storm’s 40-50 m.p.h. gusts (52 m.p.h. in Gary, Ind.), falling snow and plummeting temps proved a nightmarish combination.
This area’s heaviest snows Wednesday slashed visibilities below 1/4 mile for hours at a number of locations and left impressive snowfalls, including 4.9” at Carpentersville, 4.0” Aurora, St. Charles and Valapariso, Ind. and 2.8” at Mt. Prospect. Modestly lighter amounts (under 2”) fell in Chicago close to the lake.
-Tom Skilling

The most significant punch of cold, early season arctic air since last March is set to sweep into the Chicago area once gusty NNE winds turn away from the lake Wednesday night. The downturn promises Thanksgiving temperatures ranked among the area’s coldest 25%. The predicted high of 33° Thursday—the Thanksgiving high just two years ago as well—is 10° below normal. Not since March 21 of this past spring have daytime temperatures been so cold.

The atmosphere across North America continues in a state of transition beyond the incoming cold spell. Meteorologists call this a progressive pattern. The sharp downturn predicted Thursday modifies Friday and Saturday as south winds return. The frequency with which intrusions of cold air reach the Midwest is to rise in coming days and weeks. A new storm’s rains and snows are to reach the Midwest this weekend.
-Tom Skilling

Fall 2004’s been so mild, the city hasn’t recorded a single daytime temperature lower than 46°. It’s a meteorological situation almost without precedent. Over 135 years of official records here, only 1931 had failed by Nov. 23 to produce an autumn high of 45° or lower. Other stats underscore the remarkably mild nature of the season. Only eight mornings this fall have produced temperatures of 32° or lower—far short of the 17 considered normal. That’s a situation which has been matched only six times at O’Hare since 1959.
It may be mild here—but that’s not the case to Chicago’s southwest. Winter storm watches have been posted for parts of the Texas Panhandle, where 6-8” snow may accumulate by Tuesday night.
A storm responsible for 24-36” snow in the San Gabriel Mountains outside Los Angeles, Calif., Monday is behind the wintry assault on the southern Plains. The storm’s warm sector drenched Austin (4.61”) and San Antonio (3.47”)—both daily records.

The first sunshine in a week graced Chicago Sunday, and more is expected today. However, clouds and rain will roll in on Tuesday and continue on Wednesday as a southern Plains storm heads toward the Midwest.
Colder air in the wake of the storm should change the rain to snow by Wednesday night, but with the ground still warm, no accumulations are expected here.
South Texas was inundated by torrential rainfall Sunday as a moisture-laden front stalled over the area. With a deluge falling at a rate of 2.5” an hour, the town of El Campo (70 miles southwest of Houston) received more than 15” of rain Sunday, isolating the town and prompting hundreds of water evacuations.
It has been a very wet year in south Texas. Victoria’s 2.38” of rain Sunday sent that city’s annual precipitation total to 69.25”—making 2004 the wettest year on record there with six weeks still remaining in the year.
-- Steve Kahn, WGN-TV Meterologist

With December 3, the average date for this area's first 1 inch or greater snowfall rapidly approaching, and THAT four letter word starting to show up in the weather forecasts, it seemed like this was a good weekend to gas up the snowblower (just in case)!

The Weather Bureau maintained an office in Chicago's old Federal Building from July 1, 1905 through Nov. 30, 1964. The city's official weather records were taken at this location during the period from July 1, 1905 through Dec. 31, 1925.

Weather Bureau meteorologist Ellis Burton preparing a forecast at the Federal Building during the 1950s.

National Weather Service observer Frank Wachowski at Midway Airport in 1972 preparing to brave the elements during a heavy rainstorm.

It’s been damp, overcast and, for many, downright depressing much of the week. In the wake of early Friday’s 0.65” of rain at Midway Airport and the 1”+ downpours which drenched areas to the south near Kankakee County’s Bonfield, haze and low clouds will linger Saturday morning.
The air mass is so saturated that relative humidities through Friday night had hovered at levels just shy of saturation (100 percent) for 27 of the past 28 hours.

But, it’s the average temperature of the past four days which has been so remarkable. All the cloudiness and moisture has checked the normal nighttime cooling process here. That plus October-level daytime highs have allowed the period to average 15.8 degrees above normal—an uncommon surplus any time of the year and enough to rank Nov. 16-19 as the 10th warmest in that time frame since 1871.
-Tom Skilling

See behind-the-scenes images from Tom Skilling's feature story, "Riding The Wind." Click here for the complete photo gallery.

Novembers are notoriously cloudy here. On average, the month boasts the second highest number of cloudy days each year. It’s been four days since any official sunshine has occurred here—impressive even for one of the year’s cloudiest periods. Only twice before since 1980 have longer strings of cloudy days occurred this month. And, the current round of overcast skies has the dubious distinction of being the area’s longest of any November since 1992.

This season’s complete lack of snow is pushing it closer and closer to a record as well. Only five other years since snow measurements began in the 1884-85 season have failed to produce at least a flake of snow by now. Each went on to produce sub-par seasonal snow tallies.

The recent spell of “warm” weather has November’s temp rank on the ascent. The month’s opening 18 days have become the 31st warmest in 135 years.
-Tom Skilling

The spate of mild meteorological autumn days has had some beneficial effects here since Sept. 1, among them a significant reduction in the need for home heating. The “warmth” has reduced furnace usage to just 78% of normal and to only 77% the level by this date one year ago. A second 60° day will keep the trend going Thursday until winds turn off the lake and increase Thursday night and Friday, a development which promises a return to cool, damp conditions. Milder readings return Saturday but an overall temp downturn begins Saturday night.

The run-up to Thanksgiving next week may feature a blustery storm late Tuesday likely to draw much colder air into our area with the first season’s possible snowflakes by mid-next week.
It’s also warm to the north in Minneapolis. There, this autumn ranks 10th warmest of all on record since 1891.
-Tom Skilling

Not only are double digit daytime temperature surpluses ahead in the 60° “warmth” of Wednesday and Thursday, but prospects for a record mild overnight reading here appear high. As it stands now, 55° is the mildest nighttime low on the books for November 18th (Thursday morning). It’s a benchmark set back in 1941 during World War II. Wednesday night’s predicted 55° would tie that record—a higher reading would establish a record-breaker. Low temperatures in the 50s during mid-November are rare, occurring only once every quarter century.

Big rains are setting new records in west Texas. The region has until recently been gripped by drought for years. But, Lubbock recorded 1.17” of rain Tuesday—not only a new daily record, but enough to drive that city’s November precip to 5.09”—12+ times the normal value of 0.43”. Del Rio has logged 4.45”—754% normal.
-Tom Skilling

Mild November weather surged north to the Canadian border Monday with highs approaching 60º across potions of Montana and North Dakota. The afternoon highs that reached 67º at Rapid City, S.D., and 59º at Minot, N.D., were on par with high temperatures recorded Monday in the Southeast where Atlanta reached 60º and both Albany and Valdosta (in Georgia) topped out at 67º, and were as much as 20º warmer than areas of west Texas, where Amarillo recorded 44° and El Paso 49°.
While these mild readings were not at record setting levels, they were as much as 20-25 degrees above normal, and it’s the same air mass that is headed for the Midwest in coming days. Besides the 60º highs headed for Chicago, overnight lows will likely hold in the upper 40s and lower 50s the next few nights—lofty levels well above the typical mid-40° highs expected this time of the year.

Yesterday’s near-record high pressure (Chicago’s third highest in November history) is drifting slowly east, but its influence will continue to be felt over northeast Illinois much of the week ahead. Light southerly winds on the backside of the high will combine with a significant amount of clouds to hold temperatures much above normal. Cloudiness will be especially effective after sunset, keeping nighttime lows close to normal daytime high levels. By next weekend, the high pressure will have drifted off the East Coast, and a slow-moving cold front will approach from the northwest. If computers are correct, a broad shield of rain will extend well ahead of and behind the front, leaving Chicago exposed to a three-day period of clouds, rain and slowly falling temperatures.
In Alaska, deep low pressure off its west coast has northwest Alaska under blizzard warnings while heavy rains and high winds gusting to 70 m.p.h. pound the southwest and Aleutians.

With the polar jet positioned far to the north across northern and central Canada, relatively mild temps are in store for northeast Illinois this week.

Low pressure systems are forecast to track east across central Canada and the southwestern United States leaving the northern and central portions of the country under the influence of the weak extremities of stronger weather systems far to the north and south. Light southerly winds will leave readings seasonably mild, influenced primarily by cloud cover.

This weekend has been quite wintry in the Southwest where Winter Storm warnings have highlighted heavy snow. The mountainous areas of southern Colorado and northern and central New Mexico were hardest hit with from 8 to 15 inches of new snow. The Oklahoma and Texas Panhandles will total 4 to 8 inches. Amarillo, Texas received 4 inches Saturday, the first measurable snow ever on that date.
-Paul Dailey WGN-TV Meteorologist

The area has experienced its chilliest overnight temperatures of the autumn season. But, truly cold weather has been in short supply this fall. The chilliest daytime temperature this season was the 46° high this past Monday. An analysis of weather records back to 1870 indicates only four other years have failed to produce a colder daytime high by now. Three of those four years went on to produce significantly above normal winter (December through February) temperatures.

This month’s average of 46.4° to date ranks among the warmest third of all Nov. 1-12 readings on record. Easterly winds recently off Lake Michigan and “warmer” than normal water temperatures have led to an impressive range in nighttime readings across the metro area. Friday morning lows ranged from 23°—the area’s chilliest at West Chicago—to 40° at Northerly Island on Chicago’s lakefront.
-Tom Skilling

Fall, 2004’s chilliest weather couldn’t have arrived at a more appropriate time. Friday marks the 93rd anniversary of Chicago’s largest day to next temperature plunge on record. Around 4 p.m. Nov. 11, 1911, the city’s temperature peaked at 74°—a record for the date. Just 20 hours later on Nov. 12, the mercury had skidded to a bonechilling 13°—a plunge of 61°. It’s the greatest 24 hour temp change on record here.

Friday’s predicted 45° high isn’t nearly as extreme. But, it’s lower than the 46° high recorded Monday, Nov. 8, the season’s chilliest daytime temp to date.

Despite the chill, Chicagoans are enjoying a third consecutive month of above normal temperatures. November, 2004 is running a 4.3° above normal. Even more impressive, however, is the fact this month is averaging nearly 6° warmer than the same period a year ago.
-Tom Skilling

Blown out Windows
Sixty four years ago today southwest winds with speeds as high as 65 m.p.h. swept across the city during the afternoon hours producing damage estimated at $1.5 million. There was widespread damage to trees, power lines, large signs and buildings including countless windows blown out by the high winds.

My grandfather Joseph Frank operated a mirror and glass store on Wells Street in Chicago and in the wake of that storm all of his other business was put on hold as he spent many long days replacing the broken windows!

Steve Kahn

Even though few areas on the planet are more tornado-prone than Oklahoma—and that includes much of the autumn season—reports of twisters there in November is hardly a frequent occurrence. That’s why the six twisters reported to have touched down Wednesday in the area surrounding Oklahoma City are unusual. Not since 1979 has Oklahoma County, the home turf of Oklahoma City, been visited by a November tornado. Trained spotters tracked one twister on the ground just north of Chandler for 7 minutes.

The weather was also wild Wednesday in another corner of the continent—southern Alaska.Wind gusts hit 83 m.p.h. south of Anchorage Wednesday while 5”+ rains prompted flooding at Seward on the Kenai Peninsula. The heavy, wind-driven rains on Kodiak Island exceeded 2” setting a record. Blizzard conditions left parts of Thompson Pass buried beneath 3-5 feet of snow.
-Tom Skilling

Until this year, only two other autumns have made it this far without a single sub-30° temp at O’Hare. Observations at that site have been archived by the National Weather Service since 1959—a period of 45 years. To date this fall, the coolest official temp in the city has been 31° on three occasions: Oct. 5, 17 and this past Monday, Nov. 8. That’s to change in coming days as cold Canadian air spills into the Midwest—a development which could bring low/mid 20s away from Lake Michigan by Friday morning.

While 82% of the snow seasons since 1885 have produced at least a trace of snow by this date, it hasn’t happened yet this year. But, while snow’s been in short supply, sunshine hasn’t. November is typically the area’s second cloudiest month of the year. But, 62% of the month’s possible sunshine has occurred here since Nov. 1-—an amount far in excess of the 40% which is normal.

Where to look:

Start by looking toward the northern horizon. 90% of auroral displays start there. From the northern horizon, a full blown northern lights display can expand overhead or even into a portion of the southern sky. There can be a tendency for the light to be most enhanced in the northwest and northeast quadrants of the sky.

What to look for:

Auroras may initially take on the appearance of a fog bank on the horizon. One difference between the glowing, foglike cloud on the horizon is that stars are visible through the haze. With time, the glowing cloud on the horizon can break into "arcs" of light which appear at right angles (90-degrees) to the horizon--almost like searchlight beams, but without the motion associated with such beams. These arcs often begin to pulsate and feature surges of brighter light through them at irregular intervals.

At the early stage of an auroral display, the glow appears a pale green. But, reds, blues and greens can follow fairly expeditiously in some instances.

When to look:

Pinpointing when auroras will occur or be most visible is quite difficult. This past Sunday night/Monday morning's display peaked around 12:30 am. But, astronomer Dan Joyce reports having seen the northern lights appear as early as 6pm and last to within an hour of sunrise. The best advice here is to be flexible and check back at regular intervals if an aurora isn't at first visible.

Regarding the potential for northern light Tuesday night (November 9)

A moderate to strong geomagnetic storm is reported in progress Tuesday by NOAA's Space Environment Center. Reports into the WGN-TV weather office indicate last night's overcast probably obscured a second night of northern lights Monday night/Tuesday morning. We've reached that conclusion because a viewer called from Woodruff, Wisconsin, where cloud cover wasn't the problem Monday night that it was across the Chicago metro area, and indicated a vivid aurora was visible Monday night---one which was just as impressive as the widely reported display Sunday night. Astronomers always caution that predicting auroras is tricky business and that many difficult to forecast variables are involved in producing northern lights display. But, providing the current geomagnetic storm in progress continues into Tuesday night, there may well be a third night of northern lights visible in at least sections of the Midwest, U.S. and Canada.

- Tom Skilling

The dazzling, multicolored northern lights, visible in all but 9 of the Lower 48 states Sunday night and arguably the most impressive here in 13 years, may not be the last of this cycle. While hardly a certainty, a new aurora can’t be ruled out over at least parts of the country Tuesday night. The auroral ovals, the swaths of the atmosphere circling the planet’s highest latitudes beneath which auroras are visible, are normally found much farther north—in Canada and Alaska—or south near Antarctica.
NOAA space weather forecaster Michael Weaver says a geomagnetic storm as intense as the one behind Sunday night’s aurora occurs on average only 4 times each 11-year solar cycle. While an “M-class” solar flare set off Sunday night’s celestial display, a second, more powerful “X-class” flare Sunday afternoon could mean Earth’s upper atmosphere may again be showered by charged particles and that auroral displays might reappear Tuesday night, says Triton College astronomer Dan Joyce.
Geomagnetic storms occur as energy off solar flares excite particles in earth's upper atmosphere into giving off light. High frequency radio transmissions and even electricity transmission can be disrupted during such storms.
— Tom Skilling

Sunday night's aurora display over Fermilab's Wilson Hall in Batavia, Illinois, courtesy of Martin Murphy, Fermilab Accelerator's Division Crew Chief. Thanks Martin!

Marty Eisses, an NIU alum and former WGN-TV weather office intern and now a member of the weather observation team at Midway Airport, snapped these shots of Sunday night's aurora display from the catwalk at Midway's control tower. Marty, who, like so many in the area, had never witnessed a northern lights diplay before this and was impressed at the strength of the aurora, in even in the midst of city lights. Great shots Marty!
– Tom Skilling

The spectacular aurora borealis display observed across Chicago and the Midwest Sunday night may well have this area's best in at least 13 years. That's the conclusion of our astronomer Dan Joyce of Triton College's Cernan Earth and Space Center.

The images we share here with you were relayed to us by Lisa and Tony Comaegys, photographers and owners of Aradise Productions of Michigan City. When the Comegys heard the report of northern lights while watching Sunday's (November 7, 2004) Nine O' Clock News, they jumped into their car and headed south to Purdue University's North-Central campus at Westville, Indiana, where they took this amazing set of long exposure shots.

For more images, click here.

Auroras like this one occur when earth-directed energy released from our sun by huge solar flares interacts--usually about two days later after the flare itself--with earth's magnetic field. Geomagnetic storms are creat Last night's northern lights followed what astronomers call an "M-class flare" which occurred Saturday morning, pushed the Boulder "K" index--which projects the probability of an auroral display after solar flares and coronal mass ejections on the sun----was at its highest level for nine consecutive hours Sunday night/Monday morning between 9pm and 6am, Dan Joyce tells us. We were flooded with e-mails from viewers in every corner of our WGN-TVarea reporting the breathtaking display. Jim Kean of Timmins, well to the north in Canada's eastern Ontario province, called to say the the display was visible there Sunday night as well.

A second solar flare---this one an even more powerful X-Class eruption---occurred around 4pm Sunday afternoon, according to Joyce. This, he says, could indicate an elevated potential for more northern lights Tuesday night. It's somewhat possible northern lights may reappear Monday night as well--though Dan's sense is that Tuesday offers higher prospects.

- Tom Skilling

Photo taken Sunday evening November 7 by Marty Eisses at Route 59 and I-88 in Naperville

Dazzling Display Across the Area

If you can get outside tonight in a relatively dark area, you may be treated to one of nature's greatest spectacles- the aurora borealis- more commonly called the northern lights. They are seen infrequently in Chicago, about once every two years, so tonight is a great chance to view them.

This is an Ask Tom Why question from a few years ago explaining the northern lights.

Dear Mr. Skilling:
Why do some northern lights show color and at other times they shine only white? I've seen the northern lights many times but have witnessed only on rare occasions the colors so often associated with them.
Linda Turkovich, McHenry, Ill.

Dear Linda,
The northern lights (aurora borealis) are one of nature’s most spectacular shows. The light of the aurora is caused by a stream of electrons emitted from the sun (the “solar wind”) reaching the atmosphere of the earth and colliding with atmospheric gases. Auroral colors are determined by the energy levels of the incoming electrons as well as the density and composition of the atmosphere they are passing through. When struck by the electrons, these gases become excited and emit a characteristic color.
Nitrogen tends to give off a green color, while oxygen emits both red and green hues. Since our atmosphere is 78% nitrogen, green is the most common auroral color, and frequently in weaker auroras this green appears as the “whitish” color you describe. An exceptionally energetic aurora may be predominately red, and some auroras tend to appear purple or bluish just before dawn when sunlight strikes the top of the auroral rays in the high atmosphere hundreds of miles above the observer.

Copyright © 2004, WGN-TV

Steve Kahn

Back to back mild, sunny days are unusual enough for a Chicago weekend in November, but to top it off, nighttime sky watchers were treated to an unusual visit from an aurora in the northern sky Sunday evening, especially brilliant in suburban and rural areas away from city lights.
Mostly sunny skies continue for the next few days, but Monday’s daytime highs are limited to the 40s as the core of the cold air settles over the region, with overnight lows likely the coldest of the season thus far.
Temperatures rebound back above 60° by Wednesday ahead of the next cold front sweeping south from Canada. With falling temperatures Thursday, morning rain may change to flurries before ending, bring the first touch of snow to Chicago this season.
After a cold day Friday, temperatures again begin a rebound over the weekend, with wide swings every few days not unusual in volatile November.

Chris MacDonald is a senior in Broadcast Meteorology at Valparaiso University and is an intern here at the WGN-TV Weather Center in Chicago. His enthusiasm for everything weather and his attention to detail are great! His home town is Grand Rapids, Michigan.

Saturday’s high temperature of 65° at O’Hare—13° above the normal high, teamed up with modest WSW winds and clear skies for about as nice a November day as possible in Chicago. By contrast, at this time in November, 1991, Chicago shivered through 4 consecutive days of record setting cold, peaking on Nov. 7, 1991 when the high topped at only 27° and the succeeding night dipped to 11°.

The brief cool-down over the next few days will not be close to that magnitude, but Sunday afternoon’s gusty WNW winds and falling temperatures bring the weather back to normal November levels. Temperatures rebound back toward 60° Wednesday, tapping Gulf moisture ahead of the strongest cold snap of the season. On Thursday, lingering rain turns to snow flurries as daytime temperatures fall through the 30s and overnight lows dip into the mid 20s, with only a slow moderation in days to follow.

Do it While it's Warm!

Take advantage of this beautiful "bonus" weekend to get your yard ready for winter, bring in that outdoor furniture, disconnect the hoses, etc. Temps will plunge by the end of the week with overnight lows falling into the lower 20s and daytime highs remaining in the 30s. Trust me, it's a lot better to do these annual chores in weather like today's!!

Steve Kahn

November has a windy history in the U.S. Hurricane-force gusts back in November, 1975 sent the Edmund Fitzgerald to the bottom of Lake Superior. And there was nothing lackadaisical about Friday’s winds, clocked as high as 149 m.p.h. atop New Hampshire’s Mt. Washington. The mountain towers 6,288 ft. above sea level. The raging winds there made a 12° air temp feel more like -20°.

At the same time 2,000 miles to the west in Montana’s mountains, gusts to 62 m.p.h. whipped Browning, a community just east of Glacier National Park. The powerful wind regime—a by-product of huge north to south temperature and pressure variations in western North America—also produced 11 consecutive hours of winds above 50 m.p.h. at Lethbridge in Canada’s Alberta province.

Saturday’s mild air here extends the current spell of near or above normal temperatures to 18 consecutive days—the longest since last February and March.
-Tom Skilling

Rain fell for a fourth consecutive day in Chicago Thursday, something that’s happened in early November only 4 other years since 1871. Nearly an inch accumulated with the latest storm at Midway Airport, bolstered by thundery downpours which put in an appearance predawn Thursday. Thundery weather is comparatively rare this time of year, occurring on average only once each November.
The weather has been even more unusual in other parts of the country. After another 0.36” of rain Thursday, Pittsburgh, PA’s 2004 precipitation total has grown to 52.26”—a new record. Never since 1836 has a full year produced as much precip. And, there are still 7 weeks in which to add to the tally.
Meantime, farther north, heavy snows in recent days have totaled 10.3” in Anchorage, Alaska. That’s more snow than typically falls in an entire November at the site.
-Tom Skilling

Chilly weather certainly hasn’t been absent this season. Thursday’s raw chill drives that point home. But, the number of truly chilly days is running behind the long term average here. Not only are the first days of November averaging 3.5° above normal, thanks in large part to cloud cover and easterly winds which have reduced the typical nighttime temperature decline, but meteorological autumn has hosted only two days with highs under 50°. Not since 1994 has a fall season produced so few sub-50° daytime readings. Over the 134 year term of Chicago weather records, the Sept. 1-Nov. 4 period has produced an average of 6 sub-50° days by now.

The storm behind Chicago’s clouds and rain drenched sections of the Gulf Coast Wednesday. A record 3.98” swamped Meridian, Miss. And, recent heavy rains have some rivers just above flood stage in southern Illinois.
-Tom Skilling

Tuesday’s 8.4” of snow at Amarillo, Texas is the heaviest to fall there so early in an autumn season over 112 years of official weather records. A typical season sees 17.4” in the Panhandle community. That same buried Colorado’s front range under as much as 15” of snow Monday. Its next targets are the Plains and the Midwest where big rains are expected. Slowly strengthening easterly winds in the Chicago later Wednesday are to signal the system’s approach.
Tuesday’s 49° here was the second chilliest high so far this fall. It marked only the second time since Sept. 1 an afternoon reading has failed to reach or exceed 50°.
History indicates area highs continue declining 2 to 4.6° per week for another month and a half through December’s third week—then stabilize. Still, a typical November hosts 5 days with highs at or above 60° beyond this date.
-Tom Skilling

For only the ninth time in 2004, rainfall exceeded 1” Monday over much of the Chicago metro area. The 1.07” which had been tallied at O’Hare by late Monday ranked 4th heaviest among all rains on record since 1871 on Nov. 1. The heavy rain wasn’t limited to this area. Rivers were on the rise across sections of 8 states from Texas and Lousiana north to central Illinois.
But while rain was the big story at many locations, a small tornado was reported to have touched-down at 3:35 p.m. downstate near Champaign. The twister then proceded on the ground along a 1.5-mile path averaging 100 yards wide. Preliminary reports indicate the storm tore the roofs off three barns. One of the barns was said to have been completely destroyed. The same storm whitened the lower elevations of Colorado and the western Plains for the first time this fall. Aspen Park was hit by a 15” while metropolitan Denver residents dealt with slushy highways after 2.6” fell.
-Tom Skilling

WEATHER IN SYNC WITH THE CALENDAR
As if on cue from the calendar the weather turned very November-like today-dreary, damp and chilly. Through 3:45 p.m. rainfall in Arlington Heights totaled .75" making the day a total wash-out. With temperatures hovering in the middle and upper 40s and a gusty east/northeast wind there is a raw feel to the day. Darkness is already descending over the area even though sunset is still an hour away! Looks like a good night to curl up by the fireplace!

-Steve Kahn WGN-TV