Unlike Monday, it won't take long for us to see that giant gaseous orb in the sky. As a cold front pushes away from the Stateline, it will take some of the cloud cover with it, leaving us partly cloudy.
Temperatures will be impacted but a cool north to northeast wind, peaking in the low 20s. Wind chills will likely be stuck in the teens. Tonight turns cold as radiational cooling becomes more effective. This will leave lows in the single digits.
Within this heavier band of snow visibility will be sharply reduced and there will be a quick coating of snow on surfaces, including roads. Most of the precipitation will be done before you hit the road Tuesday morning, but there could be some slick conditions where the snow did fall during the overnight. The snow will only last for about an hour in any one given location, moving near Rockford between 10pm and Midnight.
I bring positive news this week. One, we aren't going to be see as much Arctic air spill southward, meaning temperatures won't be as extremely low. And second, snow chances remain relatively low.
Afternoon highs will end up in the upper 20s today, then back down into the low 20s for Tuesday as winds turn more to the north and northeast. Expect overnight lows in the teens tonight, then single digits as we head into Wednesday morning.
Improvements continue into week's end as afternoon highs end up in the low 30s. Typically at the start of February, Rockford's average high is 30°. The one uncertainty however is the timing of the strong cold front that forecast models show pushing through late this week into the weekend.
The American model (GFS) brought the front through overnight into Thursday whereas the European model (EURO) brought the front through Friday night into Saturday. The timing of the front will play a key role into how quick we are to cool either before the weekend or as we enter Saturday. This will be hashed out in the days to come. Forecast models also didn't have a good handle on temperatures towards the end of the weekend as the GFS was much cooler than the EURO. For the time being, I left high temperatures for Saturday in the low 20s, with low 30s in place for Sunday.
Following Sunday night's snow potential, conditions will turn quieter for much of the week ahead. A dominant area of high pressure will spread over the Central U.S. through mid-week, preventing any widespread weather systems. A very brief patch of flurries may work under the incoming high pressure Monday night, but conditions will turn dry for Tuesday and Wednesday. Temperatures will remain cool, with highs in the low to mid-20s. Overnight lows will be chilly, down near the single digits with high pressure overhead Tuesday and Wednesday nights.
A stronger weather system looks to arrive between Thursday and Friday, with a strong jet aloft supporting a low pressure over the Great Lakes. This will also work for force a cold front our direction Friday morning, which will bring a pocket of cooler air to start next weekend. Temperatures will reach the 30s Thursday and early Friday but will come crashing down behind the cold front Friday evening.
Never fear though! The long-term outlooks from the Climate Prediction Center feature a better chance for above average temperatures starting next week. Northwest flow aloft will persist overhead, but the milder air that had been previously kept Southwest will inch ever closer, likely resulting in more 30s than 20s for the second week of February.
After some flurries earlier in the afternoon, our next round of light snow showers is spreading across the Stateline this evening. Some drier air may work to limit the snowflakes from reaching the ground at first, but steady snow should begin falling West of I-39 by 6:30-7PM.
Steadiest snow will reach I-39 corridor around 7PM, where visibility could drop down toward a mile in the steadiest pockets of snow. A shallow coating of snow accumulation may develop on untreated surfaces, so be on the lookout for slick spots tonight! Snow showers exit after 12AM, with lingering flurries through early Monday morning. Some very brief patches of freezing drizzle may be possible with the loss of cloud ice, but any impacts to roadways would be limited.
Saturday was a pleasantly cool day as temperatures finally cracked the 20-degree mark for the first time in over a week. Sunshine dominated the sky, making it feel warmer than the afternoon high of 24° would suggest. A continued clear sky overnight will drop out temperature back to the single digits before clouds slowly build in for Sunday morning.
Sunday will start on a cloudy note with temperatures back into the mid-20s by the afternoon. We will remain dry through at least the late morning, but a stray flurry may be possible as early as the afternoon. The evening will bring the best chance for some light but steady snow showers, finally working through the drier air above the surface.
Best coverage of any light snow will be centered between 6PM Sunday evening and 3AM Monday morning. Visibility may be limited down to a mile or less in the steadiest snow. A coating of snow may develop on roadways, causing some slick spots.
All told, most in the Stateline may be able to pick up around a half inch through Monday morning. A few locations in far NW Illinois may get slightly more than that, but 0.5" looks to be the cap for most of the area. This will be enough to coat untreated surfaces, so be cautious of slick spots beginning late Sunday evening!
It's been a long streak of arctic cold over the last week plus in the Stateline. The last 8 days have featured an average high temperature of only 10.1°, nearly 20 degrees cooler than the average for this time of year! This also marked the 8th day in a row with temperatures failing to reach 20 degrees. That is the longest such streak since February of 2021, when Rockford spent 11 days below 20.
Saturday will finally break that streak, as our high will reach back into the 20s with a partly cloudy day. We will return much closer to average over the next week, with several days in the mid to upper 20s.
This "milder" pattern comes with an active series of clippers. The first of which will bring the potential for some light snow or flurries Sunday afternoon and evening. System number two may pass just South of us with higher pressure blocking abundant moisture from reaching this far North. A stronger system will pass us by late in the week, bringing yet another slim chance for snow Thursday into Friday, along with a sharper cool-down into next weekend.
