We usually think in terms of a couple months when we think about winter turning into spring, but the weather pattern is changing so quickly now that it might all happen this week. A scant five days will separate Sunday’s snow and today’s flurries from highs in the lower 60s later this week.
The 1-3 inches of snow that had fallen across the Chicago area as of Sunday evening ended a 22-day “mini snow drought” that had prevailed since Feb. 11 when 1.2” fell. On average, only seven days elapse between accumulating snows at this time of the year.
Midway Airport weather statistician Frank Wachowski reports that Sunday’s snow brings the city’s seasonal snow total to 29 inches, and that is 68 percent of the full-season total of 42.9” that normally falls at Midway.
A major weather pattern change is taking place, and for Chicago that means higher temperatures and showery weather. At least some rain is expected on four of the next six days.
–Richard Koeneman, WGN Weather Center meteorologist
The upcoming week begins on a wintry note with the city facing a slushy accumulation of an inch of snow, possibly 2-4″ out toward Rockford and up into southern Wisconsin as a clipper system races southeast into the Ohio Valley.
This will be the city’s first measurable snowfall in three weeks (1.2″ fell on Feb. 11) and the most snowcover since 4″ on Jan. 20.
True to its volatile nature, March will show its spring face by the end of the week as a major weather pattern realignment occurs. The western United States, which has been mild and rather dry, has begun to turn stormy and colder, whereas the Midwest, which has been chilly and dry, will be turning showery and warmer.
March opens the severe thunderstorm season in Chicago, and the National Weather Service has designated March 5-11 as Severe Weather Awareness Week for Illinois and Indiana. The Weather Service has scheduled drills and exercises to prepare the public.
Saturday’s sunny weather masks the approach of accumulating late-season snow, expected to reach the area Sunday and fall steadily for 6 to 10 hours. As much as 2-4” could fall, though above-freezing pre-storm temperatures Saturday may complicate the accumulation picture by elevating ground and pavement temperatures. The system behind the potential for a late-weekend snow here generated 8-18” totals in California’s Sierra Nevada mountains Friday—only days after peaks there were smothered by 4 foot accumulations.
It hasn’t snowed measurably in Chicago since Feb. 11—more than three weeks ago. The area, still in the midst of a year-long drought, has gone 16 days without measurable precipitation—the longest stretch since a 17-day run extending from last Aug. 21 to Sept. 6.
If 2.6” or more snow falls here Sunday, it would exceed February’s total snowfall to date (2.5”).
–Tom Skilling, WGN-TV Meteorologist
The Chicago area’s never been treated to 80° earlier than on this date 32 years ago in 1974. The reading was nearly a month and a half ahead of the average April 22 date on which 80° first arrives each year at Midway Airport. Friday’s high will struggle to reach the mid 30s—45° lower than the 1974 benchmark.
An eastbound disturbance, currently a Pacific storm, threatens to bring wet snow or a mix of precipitation to the city as early as Sunday. Some accumulation isn’t out of the question especially Sunday night. With seasonal snowfall here (20.3”), the lowest at this point of a season in 10 years, some late weekend snow wouldn’t be all bad.
We’ve posted a list of speakers who are to join us Saturday April 8 at our 25th annual Fermilab Tornado Seminar in Batavia. Check it out at wgntv.com and follow the links to our weather blog.
In 135 years official observations, temperatures here have increased faster in March than any other month. Normal highs surge from 40° on the 1st to 52° on the 31st. Seasonal warming sends more than 50% of daytime readings above 40° for the time each year on March 8. And, the city’s first 70° temperature each year arrives at Midway Airport around March 26.
Blustery east winds all but extinguished daytime warming Wednesday in Chicago and lakeside areas. South suburban highs reached the 50s—a level achieved for a brief time in some far west suburban locations like Aurora—but fell back to the 30s and 40s later in the day.
A disturbance increases cloud and snow shower development as it passes Thursday afternoon. But, the atmospheric offshoot of an eastern Pacific storm could deliver a better organized area of snow by Sunday night and into Monday morning, possibly starting as a mixture.
Now that the three-month meteorological spring season is underway, history tells us the area’s “normal” daytime highs are likely to surge an average of 35 degrees over the coming three months and that sunshine here is to expand by well over three hours. But, it’s quite likely the area—despite a lackluster 20.3” season snow tally to date—hasn’t seen the last snow. Weather records indicate snow has fallen measurably beyond March 1 an average of six times totaling 8.1”. The numbers in a particular year can vary widely. A March 25-26 snowstorm in 1930 generated 22.3” of snow—one of the city’s biggest single snows ever. Another March snowstorm a year later between the 7th and 9th buried the area beneath 19.5”.
A few flurries are possible Thursday, but a disturbance Sunday night and Monday is the first with even the potential to produce more. That’s far enough into the future to suggest that system isn’t yet carved in stone.
–Tom Skilling, WGN-TV Meteorologist
Another mild meteorological winter, the warmest here in four years and 7th of the past ten years to finish with an above average temperature, closes as February concludes Tuesday night. The December through February period’s 29.1° temperature ranks 38th mildest of the 135 winters on file since 1871 and 2.4° above the long term average for that period.
Chicagoans get reaquainted with an all too familiar feature of spring weather here for a second day Tuesday—northeast winds. It’s the wind direction of choice here through March, April, May and June, detested by many because of its tendency to short-circuit warming.
Chilly NE winds limited Chicago’s temperatures to the 30s Monday—20°+ colder than downstate readings, including 59° highs at Springfield, Bloomington and Lincoln. Warmth farther west established new records at Denver (73°) and at Grand Island, (77°) and North Platte (75°)—both in Nebraska.
The static electricity had to be near a maximum in Chicago yesterday afternoon as the relative humidity officially dropped to 17 percent at O’Hare Airport. This was the second driest February day in Chicago since 1900 (humidity records are unreliable before that time) and tied for the ninth driest all-time. Continental-source high pressure centered over southern Illinois was responsible for this rare occurrence.
Meanwhile, Californians were bracing for just the opposite—a strong low pressure system slamming into the West Coast. High wind warnings (50-70 m.p.h.) were posted for the west slopes of the Sierra Nevada Mountains along with winter storm warnings projecting as much as 6 feet of new snow above 8,000 feet and a foot or more at lower elevations. Downpours of an inch per hour were forecast for some areas with flash flood warnings up for most of the state, and mudslides were expected in recent burn areas in southwest California.
–Paul Dailey, WGN Weather Center Meteorologist
While March will probably not “roar in like a lion” this year, the first few days of the month will give Chicagoans a “feel” that spring 2006 is on it’s way. Climatology records tell us that Feb. 28 is the average date of the first occurring 60° or higher temperature in Chicago, and it might not be far off the mark this time around as the highs on Wednesday (March 1) may possibly reach the 60s at least in southern sections of the metro area. Showers and possibly even thunderstorms will probably accompany the warmer air Friday and Saturday. The passage of a strong cold front should mark a sudden change to colder next Sunday. Below normal readings will then hold over the Great Lakes well into the following week before the next storm system brings another spring-like surge of warm air and thunderstorms.
California is bracing for a tough week ahead with winter storm warnings issued for heavy snow in higher elevations while flood-producing rains are anticipated.
Friday’s weather was a study in contrasts, with springlike 60s less than 250 miles west of Chicago at the same time snow accumulated at a rate of 2” an hour to the north on the shores of Lake Superior. Duluth, Minn., was hit by 9” in just five hours while nearby Adolph, Minn., was home to the Midwest’s heaviest daytime snow tally of 14”.
Snow stands more than two feet deep across much of Michigan’s Upper Peninsula.
Though February’s 1.80” monthly precipitation in Chicago is headed for the books as the second consecutive month to produce a surplus, it hasn’t rained or snowed here at O’Hare, the city’s official observation site, in 9 days—the longest dry spell since a 14-day stretch four months ago from Oct. 3 through the 16th.
This final weekend of meteorological winter 2005-06 is to feel the part with daytime 30s. But, six years ago, Chicago’s temperature soared to 72°—a record for this date.
—Tom Skilling, WGN-TV meteorologist