Soggy and Wintry Weekend Follows Record-Breaking Warmth

Every time we have well-above average temperatures spill into the region, I wish we can just bottle it up and keep it around. Not only did the last two days feature plenty of sunshine, but also record warmth. Wednesday's high of 55° is now the warmest December 9th on record. Following that, Thursday's high of 57° tied for the warmest December 10th on record for the Rockford area. Like I said, I wish we could continue that lovely stretch of weather into the upcoming weekend. But as we've been mentioned all week, we've been keeping an eye on a storm system that will not only bring that winter-like chill back, but also the potential for snow accumulations.

Before you head out the door this morning, I would make sure to have the rain gear with you. Although you'll walk out to cloudy skies, rain chances are not to far behind. Rain to the west will begin to move in by the mid-late morning hours, becoming steadier as we head into the afternoon. High temperatures, thanks to the rain and a northeasterly breeze, will end up in the low 40s. If you're keeping score, highs today will end up about 10 to 15 degrees cool than highs Thursday afternoon. We'll see this cold and steady rain continue into the evening commute, possibly mixing in with a couple of snowflakes. Please be sure to take extra caution as you make your home this evening. 

What's been the two biggest questions about this storm system has been, "how much cold air will this system have to work with?", and "when will we see that transition to snow?". What we need to pay attention to is the freezing line, or where temperatures are flirting with 32°. Models have been consistent with the 32° line staying to our north overnight tonight, and into the early hours of Saturday morning. This means that the snow bands will mainly remain to our north and west, but I wouldn't rule out a few snowflakes mixing in from time to time.Once the low tracks to the south of the Stateline by Saturday morning, temperatures will slowly crash into the afternoon. This will help pull that freezing line southeastward, allowing the transition to snow to take place by mid to late morning.

For those areas that are expected to see more snowfall accumulations from this system, the National Weather Service has placed a few of our counties under a Winter Weather Advisory. Green and Rock counties up in southern Wisconsin are under that advisory from midnight tonight until 6PM Saturday evening. Jo-Daviess and Stephenson counties here in northern Illinois are also under that advisory from 6 PM this evening until 6PM Saturday evening. If you have any traveling plan on Saturday, take extra caution because roads are going to be slick and slushy. 

This has been a tricky system to forecast. But it has become clear that the highest snowfall totals will end up in areas to the north and west of Rockford. Especially in southern Wisconsin. It has also become clear that because this storm system doesn't have a lot of cold air to work with, the there will be a sharp cutoff in accumulations. Areas to the southeast will experience more rain than snow with this event, so we're expecting totals to be at or below an inch. Closer to the Rockford and Freeport areas, totals could range from 1" to 3", with totals over 3" more like for far northwest Illinois and southern Wisconsin. After a soggy and wintry start to the weekend, the weather dries out late Saturday evening into Saturday nigh, with the possibility of some sunshine returning by Sunday.