From Shoveling To Shivering
A Full Menu Of Wintry Weather
We will experience some of the worst wintry weather mother nature can offer over the next few days. First, we have a light mix of rain, freezing rain and snow possible at times through midday. That should transition over to moderate to heavy snow from the middle of the afternoon into early tonight. An Arctic front flies through the area tonight which could be accompanied by a flash freeze and near white-out conditions. Wind chills will plummet to well below zero overnight and by Sunday morning we will be flirting with record lows.
Most of today's snow should fall from between 2 pm and 7 pm. The latest GFS model model shows two rounds of significant snow between today and early next week. Today's system could squeeze out 2" to 5" of fresh snow. Late next Monday into Tuesday another round of snow could potentially produce similar amounts.
There is a tiny bump early Sunday morning on the the above meteogram too. While this model doesn't show much accumulation with this system, other models suggest at least some minor accumulation. The accumulated snowfall meteogram for O'Hare (below) considers not just the GFS model but many different computer models. Some of the other models squeeze out as much as 2" to 4" with the weekend system.
The GFS model model's snowfall accumulation forecast through Friday morning has a total of around 3" to nearly 6" falling across northern Illinois and Indiana. It squeezes out around 4" in Chicago.
The European model lays down around 3" to 5" for this first round of snow. It suggests about 4" in the city.
The heaviest snow will fall right in the middle of these evening's commute. The National Weather Service has most of us under a winter weather advisory from 11 AM today until 2 PM Friday. Winter storm warnings are posted for northwest Illinois.
Highs today will climb into the lower 30s but a dramatic drop is coming tonight. That drop is accompanied by winds gusting over 40 mph to send wind chills well below zero. They will remain there through Friday and most of the weekend.
Record Breaking Temperatures?
The GFS model has been warning of a brutal, bitter blast of Arctic air that could send Sunday morning's lows to record levels. The record low for Sunday is -10°. It is a record that goes back 146 years. The model has lows that morning around -15° to -22°. Other models don't have us quite as cold though. Regardless of whether the record falls or not, it is going to be the coldest air of the season so far and possibly the coldest in at least two years.
The GFS model keeps the sub-zero cold coming. Saturday morning's forecast temperatures (lower left) drop to -3° to -10°. Monday morning's forecast temperatures (lower right) drop to -2° to -11°.
Stacking Up The Snow
The GFS model run out through Tuesday morning has a total of 7" to nearly 11" of snow coming between now and then. About half of that today into tonight and nearly half of that coming late Monday into Tuesday.
The European model lays down about 7" to a bit more than 9" between now and Tuesday morning.
The dark blue bullseye on the long range temperature probability forecasts is almost over Chicago. This means the Arctic air that arrives tonight may make frequent visits well into the middle of this month. The latest 6-10 day temperature probability forecast has the Chicago area outlooked for below average temperatures overall from February 9th through February 13th. The longer range 8-14 day forecast continues to keep us outlooked for below average temperatures overall from February 11th through February 17th.
The even longer range Subseasonal Experiment (SubX) forecast seems to suggest February will stay frigid (overall) through nearly the end of the month. The forecasts for both the week ending February 19th and the week ending February 26th have us favored for below average temperatures overall.
Storm Track Staying South?
The long range temperature probability forecasts seem to suggest the main storm track that has kept us in an active pattern for snow recently could be sliding south. At the very least, this might reflect an abundance of dry Arctic air in our area for the middle part of the month. The 6-10 day forecast favors us for below average precipitation overall from February 9th through February 13th. The 8-14 day forecast keeps us outlooked for below average precipitation overall from February 11th through February 17th.
Here is my 7 day forecast:
Today: Light mix possible through midday then moderate to heavy snow, blustery High: 36
Tonight: Snow heavy early tapering to flurries, blustery, blowing & drifting snow Low: 9
(Total accumulations by early Friday around 2 to 5 inches with the heavier end of that range north and west of the city. Around and inch or two south of the city.)
Friday: Patchy blowing & drifting snow, mostly cloudy, flurries, blustery High: 14
Saturday: Mostly cloudy, light snow possible late Low: 2 High: 11
Sunday: Partly to mostly cloudy Low: -8 High: 8
Monday: Becoming mostly cloudy, light snow possible late Low: -2 High: 16
Tuesday: Partly to mostly sunny Low: -1 High: 15
Wednesday: Partly to mostly sunny Low: 11 High: 15