Aside from the winter storm that swept through before New Year’s Eve, the phrase “accumulating snow” has been rarely used this winter. As we’ve been hinting at all week, our next storm system, which will make it’s presence known by this afternoon, will likely change that.
For a brief moment last night, Rockford observed mostly clear skies, allowing temperatures to just make it down into the upper 20s this morning. However, with our next system fast approaching, moisture was quick to increase early on, leaving the Stateline under a blanket of clouds. Despite the cloud cover, dry conditions hold on into late-morning thanks to a pocket of dry air in the low-levels. Areas to the west of Rockford, such as Freeport, Galena, Savanna, and even Monroe up in Green County, a mix of rain and snow possible before noon. For that reason, the National Weather Service has placed Green County in Southern Wisconsin, along with Jo-Daviess, Stephenson, and Carroll Counties in Northern Illinois, under a Winter Weather Advisory from 9AM this morning to 6 PM this evening.
As that pocket of dry air erodes, precipitation chances will likely be on the rise closer to mid-day. This will start out as a very chilly rain, or a mix of rain and snow, as temperatures ahead of the approaching cold front will climb into the mid to upper 30s. Once that cold front slides through the region, a colder air mass will be quick to filter into the low-levels. This injection of cold air will likely lead to a changeover to snow by late this afternoon, just in time for the evening commute. Snow later on today could be heavy at times, and will cause a reduction in visibility for those who are traveling home from work later on. Road conditions will also deteriorate with time, becoming slick throughout the evening. To be on the safe side, take it slow and give yourself enough following distance between you and other cars.
Once the low’s center is directly to the west of the Stateline, mainly over eastern Iowa, dry air will begin to filter in from the southwest. This is the part of the low-pressure system which meteorologists call the “dry slot”, or the area of the low which holds the highest amount of dry air. Hi-res models have been consistent on that moving on in late this evening, allowing for snow to slowly taper off to a few snow showers. A few flurries continue through early Friday morning, but the potential for accumulating snow looks to be much much lower. Plan for at least slower commute times early Friday, as slick spots are still possible.
Now, the question that everyone wants to know. How much snow can we expect? Will I need to prepare to shovel Friday morning? Throughout the duration of this late-week event, snow totals look to be highest to the north and west of Rockford. I think much of the Stateline will see snowfall totals in the range of 1″-3″, with areas under the Winter Weather Advisory seeing between 2″-4″. Not as much snow as what we encountered towards the end of 2021, but just enough to be a nuisance.