One Storm Winds Down As Another Comes Into Focus
Updated 2:58 pm
Some snowfall amounts:
5 Oak Park
4.8 Lake Zurich
Putting A Dent In Snowfall Deficit
O'Hare picked up over nearly 6" of snow as of this afternoon bringing the total for this winter to around 13.7". That is a bit more than 3.1" below average. A potential weekend storm could push us above average if some of the early forecasts verify.
This is the most snow we have seen from a single storm in nearly two years. The 5.8" of snowfall at O'Hare surpasses the 5.4" that fell on April 14, 2019. That was the last snowfall of over 5".
Temperatures today will hover near 30°. Gusty northeast winds though will make it feel more like the teens and twenties. Those northeast winds will have other impacts on our weather. They will whip up some big waves along our lakeshore so a lakeshore flood advisory will continue until noon. Those winds will also help generate some lake effect snow to add to our totals in areas near the lakeshore through early tomorrow. As colder air arrives with those winds the snow character will change. So far this has been a heavy, wet snow but when temperatures tumble late today and tonight the snow will become a bit lighter and more fluffy.
While there are no bitter blasts of Arctic air expected through the weekend, there will be some colder periods coming this week. Temperatures will tumble into the single digits Wednesday night into Thursday morning. Wind chills may fall to just below zero then.
Next Storm Within Sight
The GFS model cloud cover and precipitation meteogram shows accumulating snow from late today through most of Wednesday. Today's snow winds down by late in the morning but snowfall remains in the forecast through most of Wednesday with additional lake effect snow for some of us. This model picks up another storm for this weekend. It may begin with a mix late Saturday and then change over to snow that could linger into early Monday.
The accumulated snowfall meteogram for O'Hare considers not just the GFS model but many different computer models. It suggests around 2" to just over 5" depending on the particular model today. Keep in mind as of this morning many spots already saw at least one to three inches already. I boxed in another bump shown by the models for tomorrow. That is the lake effect coming on Wednesday. The early indication from these models for the weekend storm suggests about 1" to 4". More on that below.
Adding Up Snowfall Totals Through Wednesday
As of this writing early Tuesday about 1" to nearly 4" of snow has fallen in spots already. The HRRR high resolution model spits out another 1" to nearly 4" of additional snow through early Wednesday. This would mean grand totals by later Wednesday would range from about 2" to 3" well south of the city to around 6" to 8" in the city itself and areas near the lakeshore that will get lake effect snow tonight and tomorrow.
Weekend Storm To Watch
We will get a break between storms late Wednesday into early Saturday but the models are hinting at another potentially big storm late this weekend. The European model total snowfall accumulation forecast through Monday morning is eye popping. Remember this also includes snowfall from today's storm so we need to subtract at least 5" from these totals. That means the next storm could bring about a half of a foot of new snow according to this latest model run.
The GFS model also suggests significant snow is possible late this weekend. Even after subtracting around 6" from these totals to account for today's storm, the model still suggests around 3" to nearly 8" with the heavier end of that range north of the city.
Don't take these amounts as written in stone. The next storm is still several days away and more than a couple of thousand miles away. A LOT could change between now and then.
Growing Blob Of Blue
The long range temperature probability forecasts still have us favored for a relatively mild start to February but there is cause for slight concern after that. The 6-10 day temperature probability forecast has the Chicago area outlooked for above average temperatures overall from January 31st through February 4th. The longer range 8-14 day forecast drops those probabilities a bit but keeps us favored for above average temperatures overall for the period from February 2nd through February 8th. Those dropping probabilities combined with the big blog of blue out west that is expanding in our direction could be signaling an eventual turn to a colder pattern. The area of the country in blue favored for below average temperatures is getting bigger and moving eastward. We'll have to wait and see if it eventually makes it to the Midwest.
The even longer range Subseasonal Experiment (SubX) forecast suggests colder air could be coming for the middle part of February. Could this be what the 6-10 day and 8-14 day forecast are hinting at? 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 Active Precip Pattern Could Continue
The long range precipitation probability forecasts keep the precipitation pattern active through the first part of February. The 6-10 day forecast favors us for above average precipitation overall from January 31st through February 4th. The 8-14 day forecast has us outlooked for above average precipitation overall from February 2nd through February 8th too.
Here is my 7 day forecast:
Today: Snow tapering off this afternoon (total accum. 4" to 8"), blustery High: 32
Wednesday: Mostly cloudy, on & off snow showers Low: 24 High: 28
Thursday: Partly to mostly sunny Low: 9 High: 25
Friday: Partly to mostly sunny Low: 12 High: 30
Saturday: Mostly cloudy, rain/snow develops late Low: 25 High: 37
Sunday: Snow Low: 28 High: 35
Monday: Snow possible early, mostly cloudy Low: 28 High: 34