FIRST SNOW OF THE SEASON EXPECTED SATURDAY

Well, that didn't take long. The transition to winter has been quick and the first chance for accumulating snow arrives Saturday. A fast-moving disturbance will track through Southern Illinois, with the first flakes likely arriving along the I-64 corridor sometime during the mid to late morning hours. Snow will likely arrive in Carbondale, Marion, and Harrisburg closer to lunchtime and into the early afternoon.

As is usually the case in Southern Illinois, this snow forecast and the expected impacts are tricky. Warm air will be moving northward throughout the day on Saturday, so temperatures will be on the rise, making snow accumulation and potential impacts challenging.

Despite temperatures above freezing, the thermal profile in the atmosphere is still supportive of snow, especially along and north of Route 13. By Saturday evening, temperatures will climb into the mid to upper 30s along the Route 13 corridor from Murphysboro, Carbondale, Marion, and Harrisburg, likely changing snow over to rain before tapering off.

Further north, temperatures will be colder along the I-64 corridor, so precipitation will remain snow and this is also where we expect the heaviest to fall. In fact, the snow could come down heavy at times between 4-9 p.m. From Nashville to Mt. Vernon to Carmi amounts of 1-2" are expected, with locally higher amounts possible, mostly on grass.

If you have travel plans to St. Louis or are heading north towards Champaign and Chicago, keep in mind that travel could be impacted by the winter weather. Plan ahead by considering leaving early or waiting until tomorrow. Meanwhile, if you're heading south, little to no impacts are expected.

Winter weather will be exiting the area Saturday night. By Sunday morning, temperatures will be dropping into the upper 20s, so there could be a few slick areas, especially on untreated surfaces.

Another round of light snow is possible Monday as another fast-moving disturbance travels through Southern Illinois Monday morning.

Behind the snow, another blast of Arctic air is expected, ushering in the coldest air of the season so far to begin the month of December. By Monday morning, temperatures will be in the 10s for the first time this season. Afternoon highs Sunday through Tuesday will only be in the low to mid 30s.