There are big weather changes underway across the U.S. which will lead to much colder Chicago temps and the city’s first chance for flakes of snow Friday and Sunday.
Temps will remain above normal Wednesday into Thursday morning.
A jet stream is roaring across the Pacific and into the Lower 48 currently and this, in coming days, will carve out a deep “trough” (i.e. “southward dip”) in the upper atmosphere above central U.S. which, in turn, is to spin-up the midweek storm. That system is to bring Chicago rain Wednesday night into Thursday.
Markedly colder air Friday is set to bring the city’s first snowflakes mixed with rain Friday. By Friday morning, the air will “feel” more than 30-degrees colder than Sunday and Monday’s 60s. This weekend is likely to be Chicago’s chilliest since February.
Here’s how much chillier the air will feel in Chicago compared to Sunday and Monday’s mid 60s:
- Friday 6am CST: The air will feel 34-degrees colder than Monday afternoon’s 60s when the wind chill then is factored in
- Saturday 6am CST: It will feel 43-deg colder
- Sunday 6am CST: 37-degrees colder
- Monday 6am CST: 54-deg colder
- Tuesday 6am CST: 43-deg colder
Full forecast details at the WGN Weather Center
No Shovels Needed Though
We’re unlikely to be shoveling with these snow systems. The ground, lake and lower atmosphere are all warm at this time of year. But temps just above the surface will be quite cold–as chilly as 18 to 25-deg a mile above local terrain Friday and 19 to 21-deg there Sunday. That means snow will be forming in the clouds and some of these flakes are likely to make it all the way to the ground where rain is likely to be mixed in.
If there’s going to be snow which sticks, even in a modest way, the Sunday system has the better chance of the two systems of producing it. But even then mixed rain can’t be ruled out and with the ground so warm, just how much might stick is highly problematic. Grassy and colder outdoor surfaces would be the location of any snow which sticks and it likely wouldn’t last long.