Thursday’s 27° high was the chilliest close to a meteorological autumn here in 22 years—since a 24° high on Nov. 30, 1983. That this past season closed as chilly as it did is ironic, considering the three month period from September through November finished well above normal—the 19th warmest of any since 1871.
The chill sets the tone for December’s opening week, expected to average nearly 12° below normal. North winds behind a series of vigorous, snow-producing disturbances predicted to sweep the area in the coming week, pull successively colder lobes of arctic air into the Midwest off a vast reservoir of frigid air which covers the central U.S. and north. These cold pushes promise to produce a succession of daily temperature deficits through at least next week. If predicted temperatures verify over the next seven days, December, 2005’s opening may rank among the Top 10 coldest on the books here.
EXPLAINER: November 2005 Archives
Despite Wednesday’s emerging sunshine, the arrival of new clouds later today signals the approach of what is likely to be the first in a series of snow systems starting late Wednesday night. By Thursday morning, as December 2005 and the first hours of meteorological winter arrive, 1-2” of snow may fall. Given the strong upper air features and cold temperatures accompanying this system, it’s even possible a few 2-3” totals may occur. Such accumulations would be the heaviest recorded the first day of December since 2.7” fell 26 years ago in 1979.
Factoring in the day’s blustery SW winds, Tuesday’s temperature plunge produced a level of chill which felt 44° colder. Actual thermometer readings plummeted from 61° to 28° in just 30 hours from noon Monday to 6 p.m. Tuesday. The pullback was the equivalent of the decline in normal temperatures which takes place between late October and mid-January.
--Tom Skilling
The weather was in rare form here with 60° temperatures Monday—but downright brutal across the Plains, a region lashed by blizzard conditions. So fierce were wind gusts there that dust and soil were mixed with the falling and blowing snow. Goodland, Kan. recorded its 9th windiest day ever since 1896, logging 64 m.p.h. wind gusts. At nearby Ruleton, winds reached hurricane force, topping out at 77 m.p.h. Flagler, Colo. clocked 79 m.p.h. winds. Farther east, sections of northeast Nebraska were coated with a thick layer of ice after 1” of freezing rain and sleet hit the area only to be followed by 8-13” of snow whipped by 50-60 m.p.h. gusts. Topping reports of snowfall was the 14” reported at Gregory, South Dakota. There, 50+ m.p.h. winds built 5 ft. drifts.
Chicago’s 61° high Monday morning was only the 89th reading in 135 years to pass 60° this late in the season. Of the 4,590 total highs at or above 60° on the books here since 1871, fewer than 2% occur November 28 or later.
Chicago’s windy, rainy warmth this morning will be short-lived as a sharp temperature downturn begins this afternoon when a strong cold front passes through the city. High temperatures the rest of the week will get no higher than the 30s, and overnight lows will drop into the 20s and eventually into the teens. Flurries are likely here on Tuesday with prospects for a shot of light snow with a system passing through the city on Thursday.
On Sunday afternoon, an intense low brought a rash of twisters to the central Plains, while blizzard conditions raged in areas to the west.
As many as 15 twisters struck on the warm east side of the storm in eastern Kansas with several reports of property damage. On the storm’s cold western flank, heavy snowfall and strong winds created blizzard conditions that resulted in a 25-car pile-up that shut down portions of Interstate 70 in eastern Colorado.
A strong late-autumn storm taking shape in the central Plains this morning will take Chicago’s temperatures on a wild roller coaster ride today through Monday. Boosted by increasingly strong southeast and south winds, readings will surge into the lower 60s later today and hold in the 50s tonight as waves of showers and even some thunderstorms roll through the city. South winds will howl Sunday night, gusting above 40 m.p.h. with the risk of damaging winds as potentially severe thunderstorms rock the city around daybreak Monday.
Temperatures will drop steadily Monday and Monday night back to more seasonable levels in the 20s and 30s.
Areas west and north of Chicago face a much different fate from this storm. Winter storm watches and warnings are posted across portions of seven states from Nebraska to Upper Michigan for a wintry potpourri of heavy snow and freezing precipitation.
Ongoing atmospheric changes as Saturday gets under way eject frigid arctic air and put in motion a dramatic 50-degree three-day temperature surge. The warming is the equivalent of a move from January to late April, only it’s condensed over a fraction of the time. From Friday morning’s 13° reading, temperatures surge to 45° Saturday and to 62° Sunday afternoon or evening. That’s shy of Sunday’s 67° record high set in 1990, but it’s still an eye-popping 20 degrees above normal—mild enough to rank among late November’s top 15 percent warmest readings on record since 1871. Friday’s 25° high was the second coldest for Nov. 25 in 135 years.
Mild air surging over retreating arctic air produced Friday evening’s dusting to 1” of snow here. But, far larger snow totals have been reported downwind of the Great Lakes. Marquette, Mich., has picked up 16.3” of snow since Wednesday, which brings its monthly total to 39.3”—that’s 22” above normal.
Winds gusted to 43 m.p.h. Thursday amid frigid January level temperatures averaging more than 20 degrees below normal. By nightfall, windchills in the area had hovered near 0° for 15 consecutive hours—and were expected to continue in that range all night. Though Thursday’s mildest temperature of 41° occurred at midnight, readings had plunged to the teens by daybreak, making it the coldest Thanksgiving daytime temperature here since the upper teens recorded in 1945. Wind gusts hit 61 m.p.h. at Chicago’s shoreline at the Harrison-Dever Crib.
Blizzard conditions Thursday led to the closure of the Mackinac Bridge for a time in northern Lower Michigan. Travel over parts of the state’s Upper Peninsula was halted by whiteout conditions brought on by nearly 50 m.p.h. gusts. The 17.8” snow tallies at Rudyard and Kinross (southwest of Sault Ste. Marie) were records for the date, while 10-12” fell near Traverse City and 6” was down on Michigan’s western shoreline.
There hasn’t been a Thanksgiving this cold in Chicago since 1956. A potent early season arctic outbreak has arrived on powerful northwest winds—stacked vertically through the atmosphere and the underbelly of a 180 m.p.h. northwesterly jet stream roaring into the country from Canada.
Surface wind gusts in excess of 40 m.p.h. at times will slash daytime temperatures 20 degrees from yesterday’s levels in the mid 40s.
Afternoon thermometer readings are likely to linger in the upper teens or low 20s—but wind chills will hold to single digits and near or just below 0° at times.
The frigid air which grips Chicago Thursday had origins 1,200 miles to the north only 24 hours ago. Its descent into the United States crushes the record warmth recorded in the Plains Wednesday. Records included 69° at Rapid City, S.D. and Hastings, Neb.
Plunging temperatures and powerful northwest winds promise Midwesterners a very cold Thanksgiving Thursday. Readings dive more than 20 degrees between Wednesday’s mild 40s once daybreak snows move on, and the frigid teens to mid 20s predicted Thursday. Gusts above 30 m.p.h. are to hold wind chills to single digits. Not since Thanksgiving 1956, when temperatures struggled to 25° and winds averaged 28 m.p.h. with 35 m.p.h. gusts has the holiday been any colder here.
More serious weather woes loom downwind of the Great Lakes for residents and travelers there. Lake-effect snow, a “no-show” in north-central Indiana and southwest Michigan Tuesday, is to make up for lost time beginning Wednesday night. Waves of snowfall over the coming two days could lead to 12”-plus accumulations at some locations. Blizzard conditions are predicted in Upper and northern Lower Michigan with powerful 50 m.p.h. gusts.
Lake snows whiten sections of northern Indiana’s snowbelt east of Porter County and north into western Lower Michigan Tuesday. Such snows fall with the greatest intensity when incoming winds have traveled farthest over open lake water. But Tuesday’s winds are to back from NNW to NW with time. This means the lake snows they support will move with time, limiting the period of most significant snowfall in any one area. This should prevent gargantuan totals. The hardest hit areas should see 3-5”—locally a bit more. These totals threaten hazardous travel conditions around the southeast end of Lake Michigan.
Much colder air hits late Wednesday night through Friday and lake snowfall in that outbreak could be more substantial, focused again on areas east of Chicago.
Incoming mild air sets up an area of overrunning light snow Tuesday night. This threatens to dust a broad swath of the Chicago area with a trace to as much as half an inch of snow.
-Tom Skilling
A cold front will move through northeast Illinois this afternoon, setting the stage for a significant drop-off in temperatures for the rest of the work week. Temperatures for the Tuesday-Friday period will average about 10 degrees below normal with the coldest day Friday when readings will probably fail to warm out of the 20s.
Light snow or flurries will be in the forecast almost daily, and with winds mostly on a northwest trajectory, heavy lake-effect snows around the south end of Lake Michigan and Northwest Indiana may develop, especially Tuesday and Friday.
Holiday travel to the northeast may be problematic, as the persistent upper air pattern dominating the eastern Northern Hemisphere responsible for our wintry chill here will impact western Pennsylvania and New York with heavy snows.
Arctic air is on hiatus this weekend after producing subfreezing temperatures for 52 bone-chilling hours. Temperatures recover noticeably Saturday despite gusty winds. Area readings near or just above 50° appear a good bet and may reach the low/mid 50s in the warmest locations. That’s a surge of 22 degrees over Thursday’s frigid January-level 28° high.
By late Friday, the powerful cold air outbreak had slashed the month’s temperature ranking in Chicago 20 slots—from 12th to 32nd warmest of 135 Novembers on record. And, at least two strong new surges of arctic air next week (after Monday) threaten to further depress the ranking.
Readings first fell below 32° at 7 a.m. Wednesday, then remained below freezing through 11:30 a.m. Friday. Winds gusted above 30 m.p.h. during at least half of that 52-hour stretch, producing a long string of single-digit wind chills. Only 21 other years since 1871 have hosted such cold weather so early in the season.
Frigid arctic air and abnormally warm Great Lakes water temperatures proved an explosive combination Thursday, setting the stage for this autumn’s heaviest lake snows. Areas of Michigan opposite Chicago were buried. Grand Rapids was hit by 8.4" while 7" fell at Sparta and 7.5" accumulated late Thursday at Scottville in southwest and west central Michigan. Farther north, snow totals were even more impressive. Traverse City sat beneath 11" by nightfall while nearby Interlochen reported 13"—and snow was still falling.
But, it was Michigan’s Upper Peninsula which boasted the heaviest totals of all. Marquette’s 17" paled in comparison to the 27" full workweek tally at Ironwood since Monday night.
Thursday’s 28° high in Chicago was the coldest here since March 2 (27°). That level of chill didn’t occur a year ago for another month.
Bitterly cold air, trapped for three weeks over Alaska and the Yukon, cut loose and roared south all the way to the Gulf of Mexico Wednesday.
The teens which greet area residents Thursday morning occur this early in fall on average only once every 17 years.
Chicago temperatures plummeted Tuesday night and Wednesday 33° in just 24 hours —from 55° to 22°—a drop equivalent to the change in normal daytime highs from late October to January. The plunge was accompanied by 24 consecutive hours of 30+ m.p.h. wind gusts which generated single digit wind chills. Coming as it did after one of the mildest November opens on the books (12th warmest of the past 135), the change was a brutal one. And the early season chill continues Thursday. A predicted high of 30° is to make November 17 the fifth coldest ever and the coldest for the date since the 14° high 46 years ago in 1959.
Dozens of twisters hopscotched across at least five states Tuesday in the third major severe weather outbreak of the past two weeks. It was the single biggest tornado count since Hurricane Rita’s remnants roared ashore on September 25, producing 47 twisters. The number of tornadoes Tuesday had reached 35 by late evening. And forecasters feared an active 1,600 mile long squall line, extending from the south Texas Gulf Coast north to the Detroit area, would produce more. November, 2005 now ranks as the the deadliest month of 2005 for tornadoes, having produced 22 fatalities. Flooding 5-10” rains were reported in southern Illinois--including 4.51” at Carbondale.
To Chicago’s north and west, wind-driven snow fell amid plummeting temperatures. Snowfall reached 6.2” at Elcho, 4.5” at LaCrosse and 4” at Wisconsin Dells—all in the Badger State—and was still accumulating beyond sunset.
With the city still reeling from Sunday’s 50 m.p.h.-plus wind gusts that brought a rash of power outages and tree damage, and central Iowa sorting through tornado damage, another potentially blockbuster November storm is gathering forces in the southern Plains. In Chicago, the storm’s impact should begin late tonight as rain and thunderstorms move in, accompanied by strong, gusty southeast winds. This storm poses another severe weather threat to the lower Mississippi Valley and the southern Midwest, and it will be followed by another round of high winds on its cold backside Tuesday night and Wednesday.
Temperatures here should plunge Tuesday night, allowing the rain to become mixed with wet snow. Wednesday should be downright wintry with snow showers, strong northwest winds and temperatures holding in the 30s—a far cry from our recent balmy days in the 60s.
An outbreak of tornadoes hop-scotched across portions of central Iowa late Saturday afternoon touching down in areas from west of Des Moines to north of Ames. No deaths were reported but extensive damage occurred in Woodward, just northwest of Des Moines. Ironically football fans at the Iowa State Cyclones’ game against Colorado were evacuated as the twisters approached the stadium at Ames. Hail, up to the size of tennis balls, also pelted the central Iowa area.
The Iowa storms and Chicago’s windy and rainy Saturday were the forerunners of an impending cold blast headed for the Midwest. Chicago’s extended warmth of Fall 2005 will come to an abrupt end this week as a blustery cold blast replete with the season’s first snow showers moves into the city.
Readings that soared to 60º or higher on 10 of the first 12 days this month will be a distant memory by Wednesday when afternoon highs should not even reach 40º.
Powerful winds sweep the area Saturday, gusting as high as 40-50 m.p.h. in the afternoon and evening. Winds of that strength are capable of producing some damage. The third autumn storm in a week is behind the high wind threat. Only days ago, waves of rain associated with this system drenched mountainous sections of southern California with 5”+ of rain. The storm’s trek across the Rockies delivered 4-8” of wind-driven snow to Colorado Friday, allowing some ski resorts to open. At the same time, the system’s warm south winds sent temperatures soaring 32 degrees above normal across the Plains, setting records at Mitchell, S.D., (77°); Bismarck, N.D. (70°); and both Valentine and North Platte, Neb. (82°).
Chicago closes in on its 1949 record of 70° Saturday, a level 20 degrees above normal. For the 10th time in November’s first 12 days the mercury will exceed 60°. That’s only happened once before between Nov. 1-12—in 1964.
Chalk up another first for 2005. Never until this year has Midway Airport gone 226 consecutive days above freezing—at least not since observations began in 1928.
This year’s persistent warmth is behind the new record. The streak of above-freezing days ended early Thursday when the mercury dipped to 31°—the first sub-freezing temperature at the South Side site since March 28.
The period which elapses between the final freezing temperature of spring and the first 32° of autumn—roughly the period between killing frosts—is also referred to as the growing season. Freezing temperatures at O’Hare first occurred Oct. 23, bringing an end to the growing season there 2-3 weeks earlier than Thursday’s close at Midway. The 226-day period above 32° was 47 days longer than the comparable period a year ago.
A sharp temperature rebound in the Plains Thursday will reach Chicago Friday afternoon—boosting readings here by 15 degrees.
Lake Superior churned under the influence of November gales Wednesday, much as it did 30 years ago when the Edmund Fitzgerald sank in estimated 30 foot seas on the Big Lake. In each case, an intense autumn storm was involved. Wednesday’s system fell a bit short of the November 10, 1975 storm, which took the ore carrier to the bottom. But, gusts reached 70 m.p.h. over open water 50 miles east of Upper Michigan’s Keewenaw Peninsula and 66 m.p.h. at Houghton County Airport—powerful enough to generate 15-20 foot swells.
The same storm’s winds whipped the Chicago area as temperatures tumbled Wednesday. Gusts reached 39 m.p.h. at O’Hare (36 m.p.h. at Midway), Fall 2005’s second strongest wind to date. The powerful flow delivered early season arctic air, slashing temperatures more than 20°—from 66° at midnight to 42° by 10 p.m.
-Tom Skilling
Midwesterners haven’t seen the last of this month’s thunderstorms. More arrive Saturday night into Sunday—and still others are predicted next Tuesday. Additional thundery weather in Chicago would bring the city’s tally of thunderstorm days this month—already the most in a November since four occurred 17 years ago in November, 1988—well above the single thunderstorm considered normal.
With record warmth so dominant this month, the huge spread in temperatures across the continent continues to support a powerful, storm-transporting jet stream draped just south of the U.S.-Canadian border. Wednesday’s gusty NW winds are being driven by the latest storm embedded within that flow. More than four dozen cities in 17 states set new temperature records Tuesday. Among them, St. Louis topped out at 82° while Austin, Texas hit 88°.
-Tom Skilling
In only 13 of the past 136 years have Chicagoans enjoyed warmer temperatures in the opening 7 days of November. Though cooler easterly winds have replaced Monday’s mild, gusty southwest flow, the first week of the month ranks as the warmest here since 1978 and the 14th warmest of the last 136 Novembers. The period’s 53.4° average temperature has soared 7.7° above the long term average dating back to 1870. Departures of that magnitude have a way of not lasting. One of Fall 2005’s coolest air masses to date arrives for a short stay later Wednesday into Friday morning. But warmth returns Saturday and may include Chicago’s third November 70°.
The current pattern may be showing the first signs of fatigue in the 1-2 week range. A chunk of frigid air off the bitter, sub-zero arctic air mass which has gripped northwest North America for more than a week, could be headed this way toward Thanksgiving.
-Tom Skilling
Gusty southwest winds will boost temperatures back into the mid 60s this afternoon and again Tuesday before a cold front moves through from the northwest Tuesday night. After a couple days under the influence of cool high pressure (but still above-average temperatures for this time of the year), computer models agree on a big warm-up this coming weekend with record highs in jeopardy both Saturday and Sunday. It is rare for Chicago to experience 70° temperatures in mid November, but once a pattern is established, it is hard to break it down. With the jet stream mean position flow west-to-east along and north of the U.S.-Canadian border, bitterly cold air is trapped in northern and central Canada, and only brief incursions of cool air are allowed to penetrate this far south. Warm air holds much more moisture, and converging winds produce strong uplift and instability, so cold frontal passages will trigger thunderstorms and the potential for severe weather.
Overnight showers and thunderstorms associated with a passing cold front will move east this morning. Indications were that welcome rainfall totals in the 0.25 to 0.75" range occurred with greatest amounts on the north side of the metro area. During the week ahead, the jet stream should hold a west-east flow over the Great Lakes and with only minor diversions south, cold air should continue to hold well north of the U.S.-Canadian border. As a result, temperatures this week are expected to see-saw from 5 to 10° above normal to as much as 20° above normal. Triggering these fluctuations will be cold fronts again Wednesday and this coming weekend. Southerly flow in advance of the fronts will pump temperatures well into the 60s midweek and again next weekend. The +100 m.p.h. jet stream will continue to direct a parade of fronts off the ocean into the pacific Northwest, resulting in heavy snows in the mountains and rain or a rain/snow mix in the valleys.
Although rainfall may be very spotty as Saturday gets under way, Chicago’s weather is predicted to deteriorate quickly this afternoon. Rain coverage increases from a few errant morning sprinkles and light showers over less than 20 percent of the area to heavier, wider-coverage rainfall likely to deliver a half an inch or more of rain in many locations before Sunday morning. If true, the storm would rank as fall 2005’s third heaviest rain-producer here to date. The rain comes in the wake of a second consecutive 70° high in November. Though cool air is to flirt with the metro area a day or two at a time over the coming week, the overall pattern is to remain mild over much of the Lower 48 east of the Rockies. Another 70° is possible as early as Tuesday. A high-altitude blocking pattern over eastern Russia—4,600 miles west of Chicago—is projected to hold into mid-November, locking this country’s mild westerly jet stream winds in place.
Thursday’s predicted 72° high becomes the 157th day of 2005 with a temperature at or above 70°—the most here in 28 years. (Chicagoans enjoyed 158 days of 70° or higher in 1977). By comparison, a typical year produces 140 such readings at O’Hare and 144 at Midway—but only 113 occur along the lake front because of cooling lake breezes part of the year there.
Highs in the 70s are rare this late in the season. Only 110 of the 17,507 above 70° temperatures recorded here since 1871—that’s just six tenths of 1% of all our 70s—have occurred in November and only 83 beyond today’s date.
Thursday’s warmth arrives on gusty winds which have transported the unseasonable temperatures nearly 800 miles over the past 24 hours. Computer-generated wind trajectories indicate only late Wednesday, the warmth was over Mississippi and Arkansas.
Chicago appears headed into rare temperature territory Thursday—at least by November standards. Should a predicted high of 72° verify, it would mark only the 84th time the mercury here has passed 70° beyond Nov. 3 in 135 years of official weather records. Put a bit differently, fewer than one half of 1% of Chicago’s high temperatures this late in the season have been as warm.
Exceptionally strong westerly jet stream winds are whisking Pacific air across the country. The already mild air warms further as it sinks out of the Rockies and into the Plains, a process which induces compressional warming—raising its temperature.
The coming warmth is in marked contrast to the record chill recorded here in early November 1991. That early season cold spell produced six new temperature records and a string of eight consecutive days below 40°.
