Lake Effect Today Then Bigger Weekend Storm Possible
A Review Of The Biggest Snow In Over 2 Years
Some two day (Tuesday & Wednesday) total snowfall amounts from this week's storm:
5" Oak Park
4.8" Lake Zurich
Here are the estimated totals for the two day event:
The 6" that fell at O'Hare was the biggest two day total since 8.4" fell on 11/25 & 11/26 back in 2018. We put a big dent in our snowfall deficit with this storm. So far this winter we have seen 13.9" of snow at the airport which is now just 3.3" below average. Our potential weekend storm could wipe that deficit away easily.
Our forecast will now focus on some frigid temperatures coming today, tonight and early tomorrow. Today's highs will be a bit below average. Highs today should top out in the upper 20s. Average highs for this date are around 31°. A brisk breeze off the lake will make it feel quite a bit colder. Wind chills will be in the teens most of the day.
Tonight's temperatures will tumble into the low single digits making it one of the coldest nights of the season so far and the coldest we'll see for at least the next week. O'Hare has only dipped into the single digits twice this winter so far. The GFS model has lows near 0° northwest of the city for tonight.
Today's breeze will diminish slightly tonight but still be strong enough to give us some frigid wind chills. Wind chills will drop into the single digits by this evening and then below zero by early tomorrow morning.
Our temperatures bounce back a bit for this weekend as we climb into the lower to middle 30s Saturday and Sunday. We hover right around average early next week with highs near 30°.
Weekend Storm To Watch
The GFS model cloud cover and precipitation meteogram lingering lake effect snow today. This will primarily be in Cook County today and then shifting into northern Indian later today tonight. Another potentially significant snow could be coming for this weekend. This model suggests it starts late Saturday and continues through early Monday. More on that below.
The accumulated snowfall meteogram for O'Hare considers not just the GFS model but many different computer models. It suggests around a dusting to about 1.5" today for areas near the lakeshore in particular. The weekend storm could produce initially around 3.5" to 5" with the brunt of it falling Saturday night into Sunday but additional lighter snow afterwards at times all the way into Monday.
There is a winter weather advisory in effect until 4 pm today for portions of Cook County. 1" to 3" of snow could fall there in total with some spots possibly pickup nearly 4".
Concentrated Snow Today But Widespread This Weekend
The GFS model shows today's lingering lake effect dumping at least another inch from Cook County through Lake and Porter Counties Indiana in total through tomorrow morning. The lake effect plumes could reach as far south as Kankakee county.
This weekend's storm will bring a broader area of possibly significant snow. The European model lays down between nearly 3" in the city and northward to as much as 6" well south of the city. It keeps the heaviest swath of snow to our south into central Illinois.
The GFS model brings the heavier snow further north with another direct hit across northern Illinois. It suggests around 6" to 8" for most. An inch or so needs to be subtracted for areas near the lakeshore because this forecast includes today's lake effect snow.
Don't take these amounts as written in stone. The next storm is still a few days away and more than a couple of thousand miles away. A LOT could change between now and then.
Blob Of Blue Gets Bluer
I commented yesterday on the long range temperature probability forecasts featuring a blob of blue that was expanding and needed to be watched. The latest forecasts don't have the blob getting much bigger but it is turning a darker shade of blue. That's an indication of a possible pattern shift for that part of the country towards a colder period. The "blue blog" is expanding a little in our direction so if this trend continues, we could be facing a colder than average period in February. We have only seen seven days this winter so far with temperatures below average. The latest 6-10 day temperature probability forecast has the Chicago area outlooked for above average temperatures overall from February 1st through February 5th. The longer range 8-14 day forecast now drops us back to about average overall from February 3rd through February 9th. This could be signaling a trend towards some colder temperatures. Stay tuned.
The even longer range Subseasonal Experiment (SubX) forecast suggests seems to support a change to a colder pattern is coming for the middle part of February. The forecasts for both the week ending February 12th and the week ending February 19th have us favored for below average temperatures overall. The drop from average gets a little more dramatic the further into February we go.
More Moisture Next Month?
The long range precipitation probability forecasts keep the precipitation pattern active past the first week of February. The 6-10 day forecast favors us for above average precipitation overall from February 1st through February 5th. The 8-14 day forecast has us outlooked for above average precipitation overall from February 3rd through February 9th too. This signal has been fairly consistent and includes the vast majority of the country.
Here is my 7 day forecast:
Today: Mostly cloudy, breezy, lake effect snow showers High: 28
Thursday: Mostly sunny Low: 9 High: 24
Friday: Partly to mostly sunny Low: 12 High: 30
Saturday: Mostly cloudy, light snow develops late Low: 23 High: 33
Sunday: On and off snow Low: 28 High: 35
Monday: Snow possible early, mostly cloudy Low: 26 High: 32
Tuesday: Partly to mostly sunny Low: 19 High: 33