5:30pm Update: Most of the precipitation has moved north and east of Rockford Tuesday evening, but drizzle and fog will persist into the night. Temperatures are in the low to mid 30's and are expected to stay in that range for the evening. However, as overnight lows drop closer to freezing (32 degrees) slick roads will possible into Wednesday morning. And for that reason, I'm keeping the First Warn Weatherisk Moderate Tuesday night.
A light mixture of rain and even a few snowflakes are possible by sunrise Wednesday with lighter snow showers headed into the afternoon. Any accumulations are expected to remain very minor.
TUESDAY MORNING UPDATE:
Areas of fog still in place this morning despite gusty easterly winds. The fog will stick around for most of the afternoon, and then again this evening.
JUST IN: Winter Weather Advisory expanded to include more of western IL through 1pm today. 1-2" of sleet possible for Stephenson, Carroll, and Whiteside counties, and 1-3" for Jo Daviess and Green counties.
Winds are picking up from the east as flurries move in. Snow and wintry mix just SW of the Stateline.
Rain will then continue through the afternoon, and can be heavy at times. I wouldn't be surprised if we heard a few rumbles of thunder.
Dry and colder air then works in by the evening helping to end the rain. Though we could still see light snow overnight into early Wednesday morning.
To the west in eastern Nebraska and western Iowa, blizzard conditions are shaping up with snowfall rates nearing 1 inch an hour. On the warm side of this system strong to severe storms are possible through the mid-south and as far north as central Indiana and southern Illinois as warm and moist air is drawn northward in advance of this system.