October 2006 Archives

Temperatures were at 62° just before 1 a.m. Tuesday morning and had crashed 25° to a reading of 37° at 8:30 a.m., just a little over 7 hours later. The same cold air mass will force temperatures to start out today in the 20s over much of the metro area and struggle to warm far into the 40s despite abundant sunshine this afternoon.

Thursday this cold air mass will be reinforced with an even colder surge of Arctic-source air with origins in the Canadian Nunavut Territory some 1200 miles to the north. Winds aloft at jet stream level from northwestern Canada into the central plains are steering cold high pressure all the way from the Arctic through central Canada into the Midwest. During the day Thursday even though the air is very dry, an upper air impulse may give snow flurries to the metro area, but 30° temperatures riding over the 50° waters of Lake Michigan could give lake effect snows in northwest and north-central Indiana.

-Paul Dailey, WGN-TV Meteorologist

Temperatures will surge to around 70º Monday as late-season warmth makes its first visit here in more than three weeks. The warm-up will be short-lived as a strong cold front passes Monday night, accompanied by a few showers that set the stage for a multiday chill-down that will last through the end of the week. Highs on Halloween will reach the low 50s, but during trick-or-treat hours it should be blustery with readings in the 40s.
High winds raked the Northeast Sunday for a second straight day with widespread tree damage and power outages due to 50-70 m.p.h. winds across portions of New York and New England. The weather observatory near the 6,288 foot summit at Mt. Washington, N.H., clocked winds at 117 m.p.h. with gusts to 143 m.p.h. as temperatures there plunged into the teens.
In the Pacific, Super-Typhoon Cimaron, one of the strongest to ever hit the Philippines, made landfall on Luzon late Sunday with gusts approaching 150 m.p.h.
--By Steve Kahn, WGN Weather Center Meteorologist

Thursday’s and Friday’s overcast was gone Saturday and temperatures responded by rebounding to the the lower 50s, though strong and gusty northwest winds made it feel cooler. Peak gusts reached 44 m.p.h. at Midway and 38 m.p.h. at O’Hare as Chicago lay on the back side of strengthening low pressure moving through the Northeast. Winds of 50-70 m.p.h. there knocked out power to more than 250,000 people in the region.
Saturday’s sun and minor warm-up was just a tease of what is to come in October’s final days. Sunday’s highs should approach 60º and Monday’s potential highs in the lower 70s promise the warmest readings here since a 66º high on October 9. Monday’s warmth should make the first early sunset (4:48 p.m. CST) commute a little easier to adjust to.
Unfortunately, the 70º warmth won’t last through Halloween, but trick-or-treaters should have dry conditions with temperatures in the upper 40s or lower 50s.
-Steve Kahn WGN-TV Meteorologist

Northwest winds “stacked” vertically from the ground tens of thousands of feet aloft into a powerhouse 180 m.p.h. jet stream combined with the intensification of a major autumn storm set the stage for a very windy day in Chicago Saturday. Peak gusts could reach or exceed 45 m.p.h. as happened Oct. 1 at O’Hare Airport and Oct. 2 at Midway. The storm, centered in Kentucky, is to deepen explosively as it races north to western New York by evening. Its central pressure is predicted to plunge over that half-day period an impressive 27 mb (0.80”)—that’s a huge drop and a development which encourages air to rush into the system at increased speeds. Wind velocities surge when that happens.
Chicago was spared the driving rains which doused areas downstate Friday, including Carbondale (2.48”) and Indianapolis (1.77”). But clouds and drizzle lingered, limiting temperature movement. By late Friday, readings varied only 1 degree here over a 34-hour period.
--By Tom Skilling, WGN-TV Chief Meteorologist

Chuck Hagen of Oak Lawn, who's shared spectacular lightning shots with us in the past, shares these photographs of our Chicago area fall colors in all their glory. Thanks Chuck!

Photos courtesy: Chuck Hagen, Oak Lawn, Illinois

The record-breaking Buffalo storm, responsible for such widespread destruction of that area's trees and the massive power outages, occurred two weeks ago (we're carrying out this posting Friday, Oct. 27). But, we thought you'd find these late-arriving photos, relayed to me from Chris and Alysha Garvin of Amherst, N.Y. (a southern suburb of Buffalo) by Joe Charlevoix, staff meteorologist of WPBN, Traverse City, Mich., interesting. Remarkably, the huge snowfall in Buffalo occurred with lake waters at 62°.

The National Weather Service's Buffalo, N.Y., forecast office has generated a fascinating explanation of the freak storm's remarkable meteorological backround indicating mammoth snow accumulations occurred despite lake temperatures of 62°!

The temperature spread between the lake surface and approximately a mile aloft plunged 43.2 degrees, a level of atmospheric instability which supported towering 25,000-30,000 foot lightning-bearing clouds. The snow/water ratio was 6 to 1 (i.e. six inches of snow occurred for each inch of water)--an extraordinarily WET snow. It's little wonder trees and power lines cames down under the weight of the waterlogged snow accumulation.

Joe Charlevoix, by the way, was a WGN-TV weather office intern years ago, and also reports that Storm Warnings have been hoisted for Lake Huron nearshore waters Saturday into Sunday (Oct. 28-29) for high winds and 8-12 foot waves!
--Tom Skilling, WGN-TV Chief Meteorologist

A cloudier, chillier, or wetter October hasn’t occurred very often here. Thursday’s 0.51” of rain at O’Hare marked the 14th day of measurable precipitation since the month began. Only five other Octobers since official weather records began here back in 1871 have registered as many or more days with water equivalent precipitation totals of 0.01” or more, the most recent of them October 1925—81 years ago. Not surprisingly, the month is on track to be the cloudiest October here in 15 years. Through Thursday, Chicago has hosted only 46% of its possible sunshine—well below the 58% considered “normal” and the 54% logged here a year ago.
Friday’s heavy overcast in Chicago sits on the northern flank of the powerful storm which deposited such wet snow accumulations in Colorado, experts fear avalanches in the state’s mountains. A swarm of 20 twisters swept southwest Kansas in the warmer air just east of the storm’s blizzard.
-Tom Skilling

A year ago as the city was emerging from a prolonged drought Chicagoans would be lamenting about missing out on another rain event, but this year after a soggy late summer and autumn it is a welcome relief. With the center of low pressure forecast to pass south through the Ohio Valley, the city expects only light rain while heavier amounts up to two inches soak downstate.
Wednesday morning’s frosty 27º low at O’Hare was the coldest of Autumn 2006 to date, and the coldest temperature to occur this early in the season in 10 years. In 2005, a reading that low did not occur until Nov. 16 when the mercury dipped to 21º. A seasonably cool weekend should follow in the wake of the storm, but it is beginning to look like the city is in store for an early Halloween treat on Monday as readings are expected to surge into the middle 60s, the warmest weather here in three weeks since a 66º on Oct. 9.
-Steve Kahn-WGN-TV Meteorologist

As one of the wettest Octobers on record winds down, the door is still open for yet another one-inch plus rainfall for the Chicago area. Rainfall totals are running an inch and a half ahead of normal at the official O’Hare observing site. Midway’s veteran weather observer Frank Wachowski has measured 6.20" of precipitation, the fourth-wettest in records dating back to 1928 and still within reach of the third-wettest 8.21" recorded back in 1941. Various computer models differ somewhat on the final track of the late work-week storm, but the consensus path up the Ohio River Valley into the eastern Great Lakes favors heavy rains over much of Indiana reaching back into northern and central Illinois. Another measure of Chicago’s unusually cold October is the fact that the month has logged five days in which the high temperature failed to reach 50°—135 years of weather records reveal that only one such chilly day is typical by Oct. 24.
-Paul Dailey WGN-TV Meteorologist

It’s hard to believe that just three weeks ago, this month opened with four days of 70º or higher, and now October 2006 is among the top 10 percent coolest of all Octobers since 1871. A testimony to how chilly it has been is evidenced by its average temperature of 50.6º, five degrees below the long-term 135-year October average of 55.6º and the coolest here since the 49.4º racked up in 1988. Monday night’s snow flurries marked the season’s second official occurrence of snow, and even more snow showers could follow by the weekend. While the flurries here brought a dusting at best, snow advisories were posted for portions of southwest Michigan where several inches of lake-effect snow were expected.
Chicago and the Midwest do not have a monopoly on the chill. Temperatures dropped below freezing Monday night as far south as Georgia, Alabama and Mississippi as the season’s first flurries fell in the Carolina mountains.
--By Steve Kahn, WGN Weather Center Meteorologist

Sunday’s highest temperature occurred shortly after midnight, and then readings fell into the upper 30s during the morning marathon run, which saw winds gusting over 25 m.p.h. and wind chills in the upper 20s. After another chilly, windy day today, a warming trend will see readings in the 50s midweek. However, the “warmer” readings (still below normal) will signal the approach of another low pressure system and significant rainfall Wednesday and Thursday. Temperatures the next seven days should average about 10 degrees below normal.
October’s precipitation total has reached 6.20 inches at Midway Airport—the 4th greatest October total at that location. Midway’s 3rd greatest total of 8.21 inches back in 1941 may seem a reach, but it is not impossible.
In the eastern Pacific, Tropical Storm Paul may reach hurricane strength today, but is expected to weaken slightly as it approaches the southern tip of Baja California on Tuesday.
--By Paul Dailey, WGN Weather Center Meteorologist

The LaSalle Bank Chicago Marathon runners face much more than a 26 mile challenge today. Starting this morning, strong winds will steer cold northern Canadian-source air into Chicago. As the morning progresses, diminishing rains will gradually change over to wet snow flurries.
Start time temperatures will be in the lower 40s and fall into the upper 30s by noon with associated wind chills dropping out of the 30s into the upper 20s. Winds may be the biggest aide and at the same time the largest obstacle. Flowing out of the northwest, 30 to 40 m.p.h. winds above the surface will slam into buildings along the route, sliding down the face of tall structures funneling even stronger flow down some streets. Stretches of other avenues may experience periods of almost eerie calm. Winds will be at the backs of runners on east and south legs and present a very intimidating headwind for those headed west and north.
-Paul Dailey WGN-TV Meteorologist

There seems little doubt Sunday is on track to become this weekend’s least appealing day meteorologically. Chilly raindrops—the aftermath of downpours predicted to sweep into the area Saturday night (after far lighter, more sporadic sprinkles or brief showers during the day)—may linger long enough to greet the tens of thousands of runners in town for the LaSalle Bank Chicago Marathon as it begins at 8 a.m. in a low 40° environment. Strengthening NW winds won’t be far behind. Gusts to 25-30 m.p.h. could be in place by late morning, a development likely to send temperatures tumbling to December-level mid-30s Sunday afternoon when snow flurries may arrive.
This extends the cooler and wetter than normal legacy of fall 2006’s weekends to date at Chicago. Seven of the opening eight weekends this season have hosted at least a day of measurable rain. Overall, Saturdays and Sundays since Sept. 2 have averaged 2 degrees below normal.
--By Tom Skilling, WGN-TV Chief Meteorologist

With autumn 2006 running so cool and wet in Chicago, it would be natural to assume the winter ahead might continue the trend and turn exceptionally snowy. In the world of seasonal weather forecasting, no possibility can be completely ruled out. Yet, an analysis of the 11 snow seasons which have followed the area’s wettest autumns since 1885 indicate only four—that’s just 36 percent of them—have produced exceptional amounts of snow. In some cases, the totals have been very impressive, like the 82.3” of snow which fell in the 1977-78 season. But, the majority—the other 64 percent—have hosted far less than 39” of snow, which is Chicago’s long-term average since official records began here in 1885.
A warming of the equatorial Pacific and decline in the strength of the easterly winds there—the phenomenon referred to as El Niño—has also tended to suppress winter snowfall. We’ll continue to monitor conditions leading into the coming cold season.
--By Tom Skilling, WGN-TV Chief Meteorologist

My meteorological colleague here at WGN-TV Richard Koeneman shares this photo of fog in the valleys of western North Carolina outside Asheville. Richard took this photo at 10 a.m. this morning (Thursday, Oct. 19, 2006) from the deck of his home at the 3,650 foot level there. We thought
you'd enjoy seeing it.
--Tom Skilling, WGN-TV Chief Meteorologist

If you’ve sensed this autumn has been a bit gloomier than normal, you’re right. Not only has precipitation been twice normal, Chicago has seen less than half (49%) of its possible October sunshine—far less than the 58% considered normal. September wasn’t any better. Only 51% of possible sunshine occurred, 11% below normal. Together, September and October have been Chicago’s cloudiest in 15 years.
Wednesday’s weather varied widely across the nation. While Florida’s Daytona Beach and West Palm Beach established new records of 90°, sections of Wyoming shivered with single -digit morning lows. Readings dipped to 2° at Laramie and 3° at Rawlins under fresh snow cover. Northern Nebraska and southeast South Dakota were also blanketed by early season snow.
Thundery downpours re-erupted on the Gulf Coast Wednesday. By evening, Doppler radar rain estimates reached 6-8” in parts of south Texas and Louisiana.
--By Tom Skilling, WGN-TV Chief Meteorologist

This year’s meteorological autumn season is proving unusually cool. In the 104 years since 1902, only four other Sept. 1 through Oct. 18 periods have been chillier than this year’s 55.9°—the most recent in 1993. The clues have been all around us, from the earliest measurable snowfall just under a week ago at Midway and O’Hare to the estimated doubling in the use of home heating which has occurred in the past 7 weeks. What’s more, breaks from the chill have been few and far between. The area has hosted 21% fewer days with temperatures 70° or warmer since Sep. 1 and October alone is running 6.7° behind the same period a year ago—54.1° versus 60.8°.
Frequent rainfall and reduced sunshine have contributed to the chill. Midway Airport’s 1.26” of rain Monday/Monday night boosted its October precipitation to 5.75”—more than twice the normal and the 5th wettest for the month since records began at the South Side site in 1928.
-Tom Skilling WGNTV Meteorologist

Overnight rains taper off this morning as the northern portion of a major low pressure system moves east of this area. The southeastern U.S. is expecting severe storms and flood-producing heavy rains today; while here in Chicago bits of sunshine allow readings to warm into the 60s this afternoon, perhaps the warmest readings for the week ahead. A cold front Wednesday will be followed by cooler high pressure Thursday and sunny skies but below normal temperatures Friday. The approach of low pressure out of the central plains will bring rain as early as Friday night with clouds and showers continuing Saturday and Saturday night as the low tracks through southern Wisconsin. Occasionally heavy rains may be associated with this system. Strong northwest winds will pull cold air out of central Canada into northern Illinois with high temperatures Sunday probably occurring early in the day.
-Paul Dailey WGN-TV Meteorologist

Chicago is in for a mostly cloudy week with frequent periods of precipitation as a series of storm systems traverse the nation, but it appears the heaviest rainfall will fall to the south across the Gulf Coast region.
It seems incongruous that a part of the country so heavily flooded by last year’s hurricane rainfall could be heading into drought, but that is exactly the case after a relatively dry summer coupled with this fall’s lack of hurricane activity. That situation could ease this week as low pressure over south Texas heads northeast, bringing the prospect for copious rains to the region.
This same system brought severe weather and flooding to the Southwest Saturday, and heavy rainfall and severe weather to west Texas and southeast New Mexico Sunday.
In Texas, nearly 4 inches of rain soaked Wichita Falls and 65 m.p.h. wind gusts raked Plainview; golf-ball-sized hail pelted Loving, N.M.
--By Steve Kahn, WGN Weather Center Meteorologist

Temperatures will be on the rebound Sunday and early this week as the mercury returns to more seasonably levels after last week’s premature bout with snow and cold. The warm-up will come at a price however, as the city braces for another heavy rainfall event, potentially the city’s eight since Aug. 1. Rain totals could top 2 inches in some areas by Tuesday afternoon as waves of showers and thunderstorms roll through the area.
This same system, still developing in the Desert Southwest brought heavy rain and flooding to areas southeast of Las Vegas Saturday. All roads were washed out at Willow Beach, Arizona just south Hoover Dam stranding 39 people as boats and campers were washed into the Colorado River. Heavy rain also brought flooding to Bryce Canyon National Park in southern Utah where up to 1.60” of rain fell. Area rivers rose three feet in just four hours.
-Steve Kahn WGN-TV Meteorologist

The mammoth autumn storm which walloped Buffalo, N.Y., with a record, lightning-punctuated 22.6” snowfall Friday simultaneously buried sections of Upper Michigan beneath 14-20”. It also generated a heavy, wet cover of snow which downed trees and power lines across Lake Michigan at Hastings, Mich., (not far from Saugatuck). Nearby South Haven clocked winds of 62 m.p.h.
The storm, supercharged by a surge of record-breaking cold air directly from the arctic, attained a hurricane-like central pressure of 28.73” (973 mb) by late Friday—more intense than the deadly Edmund Fitzgerald storm’s lowest reading of 28.87” on Nov. 9-10, 1975.
Thursday’s record early season snowfall and the high winds which raked the Chicago area Friday were the system’s major impact here. Wind chills remained sub-freezing in the city for 40 consecutive hours through noon Friday.
--By Tom Skilling, WGN-TV Chief Meteorologist

It’s got to really snow for it to accumulate when soil temperatures hover near 54° as they did Thursday. Whiteout conditions were reported for brief periods Thursday morning and early afternoon, a testament to the intensity of the snowfall. Flurries have reached Chicago earlier on ten occasions since 1885. But, never in 121 years of official observations has measurable snowfall occurred earlier in the city. Thursday’s 0.3" at both Midway and O’Hare beat by 6 days the previous record for earliest measurable snow here—Oct. 18 in both 1972 and 1989. It also preceded by more than a month, Nov. 16, the average date on which measurable snow first typically occurs here. Thursday’s 39° at O’Hare and 41° at Midway were the coldest readings ever so early in the season at each site.
A chill of Thursday’s intensity rarely lingers this early. It’s likely to be nearly two months before daytime temps as cold as Thursday’s 39° high dominate.

October 12 snow.

John Kennamer of Huntley, Ill., sent us this photo of the snow in progress at his house.
Thanks, John.

Starting winter with a bang
It was like the middle of winter this morning with near zero visibility in heavy snow, temperatures in the lower 30s. The high for the day in Arlington Heights was only 37º and late this afternoon, hours after the snow ended, snow was still nearly 1.5" deep in shaded areas in my back yard.

Never before in 121 years of weather records dating back to 1885 has as much snow fallen as EARLY in a new snow season as it did Thursday. That was true not only in Chicago, but in DeKalb and Rockford as well. Across the lake, Grand Rapids, Michigan, the 1.4" of snow which had accumulated by midday was the heaviest so early in the season. On only 6 occasions in all the years since official snow measurements began in Chicago back in 1885, has snow fallen (including "traces" of snow—i.e. less than 0.1") as early or earlier, underscoring the uniqueness of Thursday's snow event.

Our National Weather Service colleagues at the Chicago Forecast Office report the first flakes of snow fell for 23 minutes at O'Hare between 1:17 am and 1:40 a.m. Thursday morning. Midway Airport didn't report snow until just after 9 a.m. For periods of 15-30 minutes, visibilities across sections of the metropolitan area dropped under 1/4 mile, lending the snowfall a truly wintry appearance---especially once it began to stick. That the snow DID stick is rather remarkable all by itself, considering ground temperatures immediately below the surface were reported at 54-degrees as recently as Wednesday evening.

The scenes produced by these rare nearly season snow accumulations—a cover of snow on autumn leaves which have only reached their peak color over the past week or two and which have only
begun to fall—can only be described as surreal—but surreal AND beautiful at the same time! Warm ground temperatures have rendered the day's accumulations fleeting, to say the least. But, before melting, 0.3" was measured officially at both Midway and O'Hare, according to veteran weather historian and climatologist Frank Wachowski. Other preliminary area accumulations which our viewers and readers have shared with us include:

1" Algonquin
1" Crystal Lake
0.5" DeKalb at Northern Illinois University
1.2" Mundelein
0.4" OakBrook
0.1" WGN studios, Chicago's northwest side

Before Thursday's snowfall, the earliest measurable snow here occurred in two different years at O'Hare International on October 18—approximately one week earlier than today's date (October 12). The first was the 0.7" which fell on October 18, 1989 and the second was a 0.2" accumulation in 1972. With southern Lake Michigan's water temperatures still averaging 60-degrees, it took the day's strong west winds to assure that lake-generated warmth wasn't a factor in lakeshore areas in deterring Thursday's snow from accumulating.

Matt Hoelter sent us these images of Thursday's unusual snowfall in McHenry County. He reports the snow showers there were dramatic in appearance as they hit but that, as in other sections of the Chicago area, they were comparatively brief. Matt reports 0.5" accumulated before melting in his backyard. Thanks for the great photos Matt!

-Tom Skilling, WGN-TV chief meteorologist

PHOTO COURTESY: Matt Hoelter

Visibilities dropped to fractions of a mile in Thursday's heaviest snow showers. This photograph taken by Jennifer Jordan from the 13th floor-level around 11:05 am this morning in Schaumburg shows one of Thursday's approaching snow showers and clearly shows its concentrated shaft of snow it produced. It's easy from this to see how heavily snow fell from some of the day's snow squalls and how accumulations occurred despite the warm ground on which the snow fell.
-Tom Skilling

PHOTO COURTESY: Jennifer Jordan

PHOTO COURTESY: Jim & Jeremy Draftz

Thanks to Steven Smith of Barrington for sharing these shots with us from Barrington.
- Tom Skilling

PHOTO COURTESY: Steven Smith

The snow which covered this rose Thursday in front of the Glenview Library illustrates the anomolous nature of the day's brief snow accumulations. Our thanks for John Lykowski, Jr. for the beautiful photograph.
-Tom Skilling

PHOTO COURTESY: John Lykowski, Jr.

By 11 a.m., Paul Voykin, grounds superintendent at Deerfield's Briarwood Country club tells us 1 and 1/4" of snow was on the ground. It proved enough for this rare early October snowman. Paul, who tells us he's referring to this shot as "Indian Summer at Briarwood Country Club", also reports Thursday's accumulating snow may only have been Deerfield's 10th or 11th snowfall this early in the season in over the past 110 years!

PHOTO COURTESY: Paul Voykin, Grounds Superintendent, Briarwood Country Club

This was the scene in Algonquin around 9:45 a.m. Thursday morning as snow accumulated despite the warm ground. Our good friend Anson Mount shares took this photo and we thank him for sharing this with us.

PHOTO COURTESY: Anson Mount, Algonquin, Illinois

In 136 years of Chicago weather records, temperatures have failed to climb above 40° only three times this early in the season. That puts the climatological odds of a reading that cold at just 2%. With Thursday’s high predicted to reach just 38°, the sub-40° early season tally since 1871 appears poised to increase to four. Not only would that reading tie the 89-year old record for the coldest October 12 daytime maximum temperature, the reading equals the normal daytime high here on Dec. 6.
The abnormal chill has prompted nighttime freeze watches and warnings across sections of 15 states from Colorado to western Pennsylvania and has reached the Chicago area in an October already running 5° behind the comparable a year ago. September and October are the only two months of 2006 which have registered sub-normal temperatures.
-Tom Skilling

The long advertised plunge into a record-challenging early season arctic air mass is just hours away as Wednesday begins. Steady, wide coverage rain greets area residents as the day gets underway. But, a southeastbound polar front swings across the city Wednesday, introducing powerful westerly winds expected to gust to 30+ m.p.h. later today and to send temperatures diving. Rush hour readings are likely to have fallen into the low or mid 40s and the coldest air since last April takes hold tonight threatening sub-freezing temperatures by morning.
The coldest temperature recorded in Chicago during the entire month of October a year ago was 48°—a reading which may be easily eclipsed by the predicted 38° high Thursday. A peak temperature at that level would put the day’s 89-year old record for the coldest Oct. 12 max temperature (38° in 1917) in jeopardy.
-Tom Skilling

Powerful southerly winds only a few thousand feet above the ground sweeping up the west end of the continent are responsible for a wavy jet stream pattern expected to deliver the Midwest one of its coldest early season shots in years. Gusts of 80-100 m.p.h. slammed into the mountains of southern Alaska, first churning up waves three stories high on the Gulf of Alaska and producing 82 m.p.h. wind gusts at Barter Island on the state’s arctic coast near ANWR (the Arctic National Wildlife Refuge). While comparatively mild and wet there, these winds are likely to powerfully push frigid arctic air south into Canada and ultimately the U.S.
The powerful cold blast they unleash could limit Thursday’s daytime readings here to the 30s and Friday’s highs to the 40s. The coldest high on record here through Oct. 12 (Thursday’s date) is 43° set on Oct. 9, 1964. Thursday’s 37° would be colder.
-Tom Skilling

Columbus Day will be cooler than this past weekend, but nothing like the cold expected later this week. Today’s slightly below-normal highs will probably be the warmest readings Chicagoans will experience until perhaps the middle of next week. The upper-air pattern is forecast to change drastically in the next 36 hours.
Presently, winds at 30,000 feet over Chicago are southwest around 40 m.p.h. with the 100 m.p.h.-plus core of the jet stream situated along the U.S./Canada border. By Wednesday, the jet stream flow will shift north-south with a core of 150 m.p.h.-plus winds just to the west through the Dakotas and western Iowa. An Arctic-source high pressure air mass will be steered directly south through Canada into the western Great Lakes and Midwest. By Thursday, there’s a good chance snow will blanket northern Wisconsin and upper Michigan, while the Chicago area is hit with record cold (highs in the 30s Thursday) and snow flurries.
--By Paul Dailey, WGN Weather Center Meteorologist

The fall transition into winter is always erratic, but this week Chicagoans will probably witness one of the more drastic atmospheric maneuvers in recent memory. Today gusty southwest winds will push warmer temps into NE Illinois in advance of a cold front approaching from the northwest. Afternoon highs should reach into the mid 70s over much of the metro area, perhaps even hitting 80° not far to the south and west. After the cold front passes tonight, tomorrow’s highs will be some 15 to 20° cooler and that is just the beginning. Showers and t-storms are expected Tuesday night and Wednesday ahead of the leading edge of an arctic-source high pressure air mass. Thursday temperatures will struggle to warm out of the 30s, along with strong gusty NW winds and wet snow showers. If snow does occur here on Thursday, it will be the earliest onset of snow in Chicago since Oct. 7, 2000 and the second earliest in 71 years.
-Paul Dailry WGN-TV meteorologist

Aided by nearly 100 percent sunshine Saturday and Sunday, southerly winds will push highs into the 70s today and perhaps even exceed 80° Sunday. However, early September-like readings this weekend will fall to early December levels in just four days.
The first shoe drops Sunday night with a moderate cold frontal passage that will lower temperatures about 20 degrees. However, the other shoe drops with a strong reinforcing cold front later Wednesday that will send temperatures reeling another 20 degrees to near-record lows. High temperatures Thursday may struggle to warm out of the 30s with Friday morning lows expected to fall into the mid to upper 20s. This would mean a 40-degree plunge from Sunday’s highs to those on Thursday, and an overall 50-degree difference between Sunday’s highs and Friday morning’s lows.
Meanwhile, heavy rains and extensive flooding are expected to continue along the mid-Atlantic coast today.
--By Paul Dailey, WGN Weather Center Meteorologist

A chill is in the air again Friday with temperatures to remain below normal a second consecutive day. It’s even possible a little patchy frost could form Friday night well away from the city proper and the warmth of Lake Michigan.
Friday’s predicted afternoon high of 63° marks only the fifth time since Meteorological Autumn began on Sept. 1 a daytime temperature has been as cool or cooler. Temperatures since the season began have averaged just 62.5°—a reading 2° below the 136 year long term average (since 1871) here, but even more impressively, 7.5° behind the comparable period a year ago. We’ve enjoyed only a quarter of last fall’s 80° days in the past 36 days—five compared to last year’s 22 by this date.
Cool as it’s been here, temperatures dipped to 28° Thursday morning at Hayward, Wisc. and 20° at Embarrass, Minn.
-Tom Skilling

There hasn’t been a wetter October open at Midway Airport and many sections of the Chicago area in more than half a century. That makes Thursday’s rain-free sun/cloud mix especially appealing. With 3.90" on the books for October 2006 at the South Side observation site, the city has received 1.4 times its normal full October precipitation allotment. The total is the city’s second highest Oct. 1-4 tally. Only the opening four days of October 1954 with 3.96” proved wetter.
The recent wet weather is only an extension of an unusally wet pattern which has gripped the area since August began. The 15.34” on the books is twice normal for the period.
A huge and currently stalled West Coast storm may impact the Midwest with significant rain late Tuesday and Wednesday.
But changes could be ahead. Six of nine years with similarly wet Aug. 1-Oct. 5 periods have turned drier than average in autumn’s final eight weeks.
-Tom Skilling

Electricity was still out late Wednesday for some residents of south-suburban Peotone, Illinois--an area hard hit by Monday evening's powerful storms. Bill Schreiber, who shot these photos and shares them with us, reports the Village of Peotone sustained quite a bit of damage and that a survey reveals damage occurred along a path 8 miles long and 3 miles wide. Included here among Bill's photos is damage sustained at a grain elevator five miles northwest of Peotone.
Tom Skilling, Chief Meteorologist, WGN-TV


PHOTO COURTESY: Bill Schreiber

Photographer Robert Feuss, who shares with us these amazing shots he took in Round Lake during Monday night's thunderstorms, says electricity in the air made the hair on his neck twitch a bit--a development which convinced him it was time to head indoors. Thanks for these incredible
shots, Robert!
-Tom Skilling



PHOTO COURTESY: Robert Feuss

Professional photographer David Mayhew shares these dramatic shots with us of Monday night's (October 2) breathtaking lightning display. Thanks David!
-Tom Skilling


PHOTO COURTESY: David Mayhew

The spectacular and frequent cloud to ground lightning which accompanied Monday's waves of thunderstorms was, to put it mildly, stunning! Arpan Shah shares these lightning shots he took from the Gold Coast.
-Tom Skilling


PHOTO COURTESY: Arpan Shah

The 55,000 ft. tall thunderstorms Monday evening (October 2) across the Chicago metro area produced straightline wind gusts estimated as high as 80-100 mph at the hardest hit locations and produced these huge hailstones in southwest suburban Plainfield. Mike Webb reports hail the size of quarters grew to golfball size as the storm proceeded and provided us these photos which he snapped around 7:30 p.m. Thanks Mike! Veteran National Weather Service observer Frank Wachowski says the waves of storms which swept the area Monday evening are the worst in an October here since a series of powerful thunderstorms lambasted this area in October, 1954.
-Tom Skilling, WGN-TV Chief Meteorologist


PHOTO COURTESY: Mike Webb

Even though today’s temperatures will average only 3° below normal, it will “feel” much colder to many Chicagoans who will experience a 15°+ drop from yesterday’s July-like readings. A warm front oriented northwest-southeast over the city brought easterly winds and 70° temperatures to the north while south of the front highs warmed into the mid to upper 80s. Farther south and west highs in the low to mid 90s, some 20 to 25° above normal, established new October benchmarks at Moline, Springfield and Peoria. After Monday’s drenching rains, the rainfall total of 15.27" since August 1st at Midway is the third greatest for that period in that station’s history dating back to 1928. While most Northeast Illinois’ soils are saturated and additional rains are forecast today, a welcome week of drying looms ahead. Rain-free high pressure will dominate the weather pattern for the next seven days, punctuated only by a weak cold front this Sunday.
-Paul Dailey, WGN-TV Meteorologist

Patrick Skach of Oak Brook forwarded us these photos of mammatus clouds taken at 6 p.m. Monday evening just southwest of Oak Brook. These cottony clouds were taken following clusters of active thunderstorms Monday afternoon.
-Bill Snyder WGN-TV Weather

PHOTO COURTESY: Patrick Skach

Less cloudiness may allow readings to jump into the 80s over much of the metro area today. But this heating could again lead into thunderheads, some possibly severe, later this afternoon and evening. As the approaching cold front nears northeast Illinois, the best chance of rain may actually occur after midnight. Yesterday’s storms were widespread and developed earlier in the day than anticipated, still temperatures warmed into the 80s (even reaching 91° at Kankakee) in many areas before the extensive cloudiness cut off the sun’s warmth. With the metro area under a Severe Thunderstorm Watch, storms developed quickly. The widespread violent nature of the storms, some as high as 50,000 feet tall, was depicted by more than a dozen reports of 1-inch hail. Largest was a 1.75" stone reported at Plainfield in Will County. Heaviest wind damage occurred in the Joliet area.
-Paul Dailey WGN-TV Meteorologist

The air mass poised just to the west resulted in high temperatures in the mid and upper 80s over western Illinois yesterday, and gusty southwest winds should push that same air over northeast Illinois today. Readings some 15 degrees above normal will be quite a change from the subnormal readings recorded the last seven days in September. The warm-up actually started Sunday under cloudless skies that veteran weather observer Frank Wachowski said gave the first day of 100 percent sunshine since Aug. 15!
A strong cold front preceded and accompanied by a band of showers and thunderstorms will shift winds sharply to the northeast Wednesday, resulting in daytime highs some 15 to 20 degrees cooler than Tuesday.
After a couple days with easterly winds, cool high pressure will drift east, and an increasing southerly flow will pull temperatures approaching 80° back into the Chicago area next Saturday.
--By Paul Dailey, WGN Weather Center Meteorologist