Back‑to‑back cold fronts brings temperature swings into the weekend

Skies are clear and winds are very light, meaning it is noticeably colder this morning. Temperatures and wind chill values for most Stateline locales are sitting close to or even below zero.  

 

 

  

Though we can expect more sunshine today, winds will be light out of the north and northeast, limiting our warm up to the upper 20s. 

 

 

  

Clouds will increase overnight as the first of two cold fronts sinks down from the north. With the front will also be the potential for flurries and snow showers, primarily before midday. The rest of the day will be mostly cloudy with highs in the low 30s. Even with a stronger cold front passing through the early stage of Friday, highs will end up in the upper 30s. 

  

The colder air from Friday's frontal passage will arrive Saturday, with the coldest air being focused across the Great Lakes and the northeast. This will leave highs in the mid 20s. 

This cooldown will be very brief however as a change in wind will occur as we go into next week. Winds will be more out of the southwest after a warm front pushes thorough Monday, pushing highs in the upper 30s, then low 40s Tuesday afternoon. 

Up and down pattern with few snow chances ahead

 A few weak systems will bypass the area Thursday and Friday, bringing a brief warm-up and a few light snow showers. The first system arrives Thursday morning, with the surface low pressure passing across the Great Lakes to our Northeast. A few light snow showers or flurries may be possible Thursday morning, moving out by early afternoon.

The second low pressure system will follow a very similar track across the Great Lakes, keeping the bulk of accumulating snow to our Northeast again. A few flurries or light snow showers will be possible again with this system, mainly centered around Thursday night through daybreak Friday. A stray flurry or two may be possible Friday afternoon as colder air begins to filter in, but the accumulating snow potential will wind down by daybreak Friday morning.

All told, most in the Stateline may not even get an inch of snow in total between the two systems. Highest totals will be focused to the Northeast along the track of the respective low-pressure systems, while much of the Stateline region will be left on the drier side.

While these systems are passing through, we will see a milder pattern as high temperatures push into the 30s Thursday and Friday. That comes with an increasing wind, with gusts pushing 15-25 mph out of the Southwest on Thursday. Northwest gusts of 25-35 mph may be realized on Friday as the colder air filters in. Saturday will not feature much wind, but high temperatures will be back in the 20s.

Chill gradually fades as milder air surges Into northern Illinois

A band of snow pushing through overnight has left behind slick, icy, and snow-covered spots in the counties highlighted in blue and pink. If traveling during the morning commute, be on the lookout and travel with caution. Roads are in better shape closer to the Illinois/Wisconsin border.

 

  

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.  

We stay relatively cool in the 20s for the middle of the work week, though a few ups and downs are on the horizon. Ahead of a strong cold front, afternoon highs will peak in the low 30s Thursday, then end up closer to the 40° mark Friday. As we talked about in Monday's discussion, forecast models still don't have a firm grip on the timing of said cold front. However, the colder air that spills in will be enough to push our highs back into the 20s for Saturday. 

Light snow moves in Monday night

 

A narrow band of heavy is currently moving through northeast Iowa, quickly diving east/southeast as of 9:30pm. While this band won't impact everyone in the Stateline, it will move south of Rockford to Aurora line.

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.

Slowly thawing out this week while snow chances remain slim

Winter has been somewhat split down the middle in terms of above vs. below average days. For the longest time however, it seemed the below-average stretch that we saw during the second half of January was never going to end. 

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.  

Aside from a few isolated flurries this morning and overnight tonight, the first half of the work week will be dry thanks to a high pressure system dipping down into the midsection of the lower 48. 

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.

Cool and quiet conditions expected through mid-week

 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.

Light snow showers Sunday evening

 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.