Daily Weather Explainer
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Hazy sun to put in an appearance amid mild Octoberlike temps
Nighttime cooling has produced areas of low cloudiness and fog from moisture lingering in the wake of the past week's damp weather system. When temperatures lower at night, air masses grow saturated with moisture at the point readings match the dew point. It's the instant relative humidities reach 100 percent.
Despite areas of clouds, Chicago remains a safe distance from the country's major precipitation-producing weather systems over the pre-Thanksgiving weekend -- one on the Gulf Coast with big rains and another sweeping into the Rockies. It's a situation which should allow the weekend here to remain mild, further extending one of the longest spells of above-normal November temperatures on the books. Highs are to reach the 50s Saturday through Monday -- readings 10 to 15 degrees above normal and more typical of late October than November. The number of consecutive above-normal days reaches 19 Sunday, the 2nd longest such period at Midway Airport since weather records began in 1928. Only 1999 managed more -- 25 of them.
Though winds are light Saturday -- often an impediment to breaking clouds up this time of year -- computer models indicate the layer of moisture supporting Saturday morning's clouds is quite shallow. This should permit daytime heating to mix the air, dissipating the cloudiness and allowing generous sunshine to emerge. Hazy sunshine is likely to return both Sunday and Monday.
As additional evidence of how mild it's been of late, the coldest temperature recorded this fall has been 28 degrees, and the coolest daytime high this month has been 47. A vast majority of years have produced temperatures colder than each of these readings by now: 128 of the past 137 years have recorded a colder autumn low temperature by now, and only one year (1933) has seen its lowest November daytime maximum higher than this year's 47.
Changing pattern to send temps tumbling by Thanksgiving;
potential cold December open ahead
Many indicators continue to suggest large pattern changes loom over the next two weeks -- changes likely to send temperatures broadly lower over the United States. The colder air appears likely to hit in two waves -- and there may be temporary warming between them.
Cold weather surges into the Midwest on gusty winds Tuesday afternoon and Wednesday amid chilly showers. Readings may be chilly enough to allow at least some mixed snowflakes to the reach the ground with the spells of cold rain. The chilly air is likely to hold Thanksgiving temperatures near 40 degrees. Even colder air may hit next weekend and carry into December.
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Hazy sun to put in an appearance amid mild Octoberlike temps
Nighttime cooling has produced areas of low cloudiness and fog from moisture lingering in the wake of the past week's damp weather system. When temperatures lower at night, air masses grow saturated with moisture at the point readings match the dew point. It's the instant relative humidities reach...
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It's felt cool---but temperatures have been milder than normal the past 16 days
Friday marks the 17th consecutive day of milder than normal temperatures in Chicago--one of the five longest such spells on record in the month of November at Midway Airport. Weather observations there date back to 1928. With above normal readings expected to continue into early next week, the mild...
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Clouds linger a 5th straight day and may be slow to retreat
Clouds cover area skies a 5th consecutive day Thursday and periods of rain are to continue. Wednesday's 0.17 inches at O'Hare made it the wettest day since late October. The day's 47-degree peak reading was the third consecutive day in which temperatures failed to escape the 40s. With a fourth day...
Tom Skilling, WGN-TV's chief meteorologist, hosted the 29th Annual Tornado and Severe Weather Seminar at the Fermilab National Accelerator on April 23 where speakers gathered to educate the public about the dynamics and after-effects of tornadoes and severe weather. Tom Skilling and Brian Smith, of the National Weather Service Forecast Office, created this seminar 29 years ago, holding the first event at Geneva High School auditorium with a total of 40 in attendance. Needless to say, the event has grown to must-attend national event for weather enthusiasts.
Ask Tom Why
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Similar temperatures across the nation
Dear Tom,
On the evening of Aug. 10 I was checking the weather for many cities coast to coast and they were all 79 degrees. Is that rare and is it more likely to occur in summer?
Norman Alexandroff
Dear Norman,
Having a large expanse of uniform temperatures across the nation is quite unusual and would... -
December 1945 in Chicago's warm to cold temperature swing
Dear Tom,
I was married on Dec. 8, 1945 and it was a very warm day. A week later when my friend got married on Dec. 15 it was below zero. Can you provide the details?
Delores Faltynek Antioch
Dear Delores,
We asked climatologist Frank Wachowski to check the weather archives and he found your...
Currently: 41° F
