Cloudy skies are expected Tuesday evening as temperatures hold steady in the mid 30s, dropping into the low 30s Wednesday morning. High pressure briefly moves in during the first half of the day Wednesday ahead of a deepening low-pressure system that’ll bring a mix of rain and snow to northern Illinois and southern Wisconsin.
Temperatures Wednesday afternoon will be slow to warm, reaching the upper 30s with a breezy east wind. Low pressure moving northeast from the near the panhandles of Oklahoma and Texas will move across northern Missouri Wednesday, lifting towards northern Illinois Wednesday night and Thursday morning. The current track of both the surface low and upper-level low don’t favor much accumulating snow for the Stateline, keeping higher snowfall totals to the north and west.
As a southeast wind pulls in moisture ahead of the low Wednesday night precipitation will begin as likely a rain/snow mix, with a little more snow on the leading edge after 4pm or 5pm. But as the warm air continues into the evening, the freezing line (32 degrees) will be pushed further north. This will lead to the likelihood of more rain showers, versus snow showers, during Wednesday evening. Slushy snow may still occur closer to the Illinois/Wisconsin border, and possibly over northwest Illinois, where minor accumulations are possible. There may even be a little sleet mixed in from time to time as the warmer air continues.
Temperatures Wednesday night will be close to freezing and with the wet conditions and wintry mix/rain, a few slick spots are possible during the evening commute. Drier air moving in Wednesday night and Thursday morning will bring an end to most of the steady precipitation, leading to more drizzle and fog for the morning commute.
As moisture wraps back in Thursday afternoon, we’ll see a return of the rain/snow mix before snow flurries occur Thursday evening.