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.
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.