By Meteorologist Tom Skilling
A dusting of snow---potentially as much as an inch or an inch and a half in spots---could bring the city's measurable snow drought to an end Thursday night. It's been nearly 8 months since snow has accumulated within the city limits.
Snowfall exceeding 0.1-inch in the city would be the first here since April 18
Chicago's last official "measurable" snow---defined as 0.1 inch or more---occurred nearly 8 months ago on April 18. That's when 0.6 inches of snow fell at O'Hare. It was the final sticking snow of the 2010-11 season.
Though flurries have been observed within the city limits four times this month and seven times since the snow season began this year on Nov. 9, the only "measurable snow" which has fallen has been across the northern suburbs.
That may change as a light-snow-generating disturbance swings across the metro area Thursday night. The system's approach will become more and more evident Thursday as sunshine is filtered by an influx of clouds out ahead of the disturbance's light snow, particularly Thursday afternoon and evening.
Computer models offer their "take" on area's possible snowfall
Our in-house RPM (Rapid Precision Mesoscale) weather forecast model is the most aggressive with snowfall from the incoming system, producing a wider and heavier swath of snowfall than some other models. It suggests much of the Chicago metro area is in for a measurable snow----ranging from a dusting to as much as an inch or an inch and a half in harder hit areas.
By contrast, the National Weather Service's WRF model produces snowfall but targets Chicago's south and southeast suburbs with the heaviest totals (0.6 inches up to 1.8 inches). Though it also breaks the measurable snow drought at O'Hare by generating 0.1-inch there and as much as 0.3 inches at Midway.
Time, of course, will tell how much falls and where, but the potential for snow and colder temperatures in Chicago marks a wintry turn in the city's heretofore abnormally mild early December weather regime.
Season's coldest arctic air on the move; first daytime 20s in 10 months a good bet Friday and possibly Saturday
The snowy Thursday night disturbance is forming as the coldest air of the season knifes southward into the U.S. from Canada---destined to reach Chicago Friday into Saturday. Daytime highs, once the cold air settles in, are likely to remain in the 20s Friday and possibly Saturday for the first time in the 10 months since February.
Gusty west/southwest flow to expel arctic air Sunday and Monday replacing it with milder Pacific air and 40+ degree highs
If there's any good news in the latest forecast trends, it continues to be the expectation that the cold blast will be comparatively short-lived. The gusty west to southwest winds predicted to sweep in later Saturday and Sunday will boost temperatures from 25 Friday and 28 Saturday to 43-degrees Monday. And a set of 40-degree or warmer days are predicted through mid-next week---though the passage of a weak cold front Monday night ushers northwest winds into Chicago Tuesday---which may be enough to limit highs then to the upper 30s.
Models have yet to indicate a December snowstorm here
If there's a snowstorm in Chicago's future the next two weeks, there is NO computer model consensus on it at this point. That can change fairly quickly this time of year. But for now, Thursday night's wave of light snowfall is the only definitive snow threat the metro area faces in the short term.
Occasional runs of one forecast model or another, have from time to time in recent days, picked up on a system predicted to produce snow or rain here. But, the inconsistency of these forecasts suggest the potential for a significant system is far from firm. Stay tuned! We're monitoring the situation and will let you know if and when that changes.
Storm drenches East Coast's biggest cities Wednesday; Virginia rains approach 4 inches while inland snows hit 8.5 inches in portions of Pennsylvania/New York
A wet winter storm drenched an area from near Washington D.C. north to New York and Boston Wednesday. Flooding was reported in Baltimore County and a WeatherBug rain gauge in the nation's capital measured 3.32 inches late Wednesday, while 3.78 inches was measured at Spotsylvania and 3.29 inches at Fredericksburg---both in Virginia.
Mountain snows totaling 8.5 inches were reported in the mountains of Pennsylvania and New York, where snow was still falling late Wednesday night. Heavy snowfall was predicted in Interior New England.
A dusting of snow---potentially as much as an inch or an inch and a half in spots---could bring the city's measurable snow drought to an end Thursday night. It's been nearly 8 months since snow has accumulated within the city limits.
Snowfall exceeding 0.1-inch in the city would be the first here since April 18
Chicago's last official "measurable" snow---defined as 0.1 inch or more---occurred nearly 8 months ago on April 18. That's when 0.6 inches of snow fell at O'Hare. It was the final sticking snow of the 2010-11 season.
Though flurries have been observed within the city limits four times this month and seven times since the snow season began this year on Nov. 9, the only "measurable snow" which has fallen has been across the northern suburbs.
That may change as a light-snow-generating disturbance swings across the metro area Thursday night. The system's approach will become more and more evident Thursday as sunshine is filtered by an influx of clouds out ahead of the disturbance's light snow, particularly Thursday afternoon and evening.
Computer models offer their "take" on area's possible snowfall
Our in-house RPM (Rapid Precision Mesoscale) weather forecast model is the most aggressive with snowfall from the incoming system, producing a wider and heavier swath of snowfall than some other models. It suggests much of the Chicago metro area is in for a measurable snow----ranging from a dusting to as much as an inch or an inch and a half in harder hit areas.
By contrast, the National Weather Service's WRF model produces snowfall but targets Chicago's south and southeast suburbs with the heaviest totals (0.6 inches up to 1.8 inches). Though it also breaks the measurable snow drought at O'Hare by generating 0.1-inch there and as much as 0.3 inches at Midway.
Time, of course, will tell how much falls and where, but the potential for snow and colder temperatures in Chicago marks a wintry turn in the city's heretofore abnormally mild early December weather regime.
Season's coldest arctic air on the move; first daytime 20s in 10 months a good bet Friday and possibly Saturday
The snowy Thursday night disturbance is forming as the coldest air of the season knifes southward into the U.S. from Canada---destined to reach Chicago Friday into Saturday. Daytime highs, once the cold air settles in, are likely to remain in the 20s Friday and possibly Saturday for the first time in the 10 months since February.
Gusty west/southwest flow to expel arctic air Sunday and Monday replacing it with milder Pacific air and 40+ degree highs
If there's any good news in the latest forecast trends, it continues to be the expectation that the cold blast will be comparatively short-lived. The gusty west to southwest winds predicted to sweep in later Saturday and Sunday will boost temperatures from 25 Friday and 28 Saturday to 43-degrees Monday. And a set of 40-degree or warmer days are predicted through mid-next week---though the passage of a weak cold front Monday night ushers northwest winds into Chicago Tuesday---which may be enough to limit highs then to the upper 30s.
Models have yet to indicate a December snowstorm here
If there's a snowstorm in Chicago's future the next two weeks, there is NO computer model consensus on it at this point. That can change fairly quickly this time of year. But for now, Thursday night's wave of light snowfall is the only definitive snow threat the metro area faces in the short term.
Occasional runs of one forecast model or another, have from time to time in recent days, picked up on a system predicted to produce snow or rain here. But, the inconsistency of these forecasts suggest the potential for a significant system is far from firm. Stay tuned! We're monitoring the situation and will let you know if and when that changes.
Storm drenches East Coast's biggest cities Wednesday; Virginia rains approach 4 inches while inland snows hit 8.5 inches in portions of Pennsylvania/New York
A wet winter storm drenched an area from near Washington D.C. north to New York and Boston Wednesday. Flooding was reported in Baltimore County and a WeatherBug rain gauge in the nation's capital measured 3.32 inches late Wednesday, while 3.78 inches was measured at Spotsylvania and 3.29 inches at Fredericksburg---both in Virginia.
Mountain snows totaling 8.5 inches were reported in the mountains of Pennsylvania and New York, where snow was still falling late Wednesday night. Heavy snowfall was predicted in Interior New England.
