We're kicking off the weekend with high pressure nearby allowing for lots of sun and temperatures warming into the low to mid 30's.
Weather begins to change as you head back to work on Monday with a rain snow mix possible. Some of the details have changed a bit on what we can expect.
Breaking down the set up, high pressure will build into the southeast while low pressure develops near the Rockies. With this set up, the Midwest receives southerly flow and an inflow of moisture from the Gulf. A short wave of energy will travel northeast through the middle and upper Mississippi River Valley. The wave system has been slowing down, so the beginning of precipitation doesn't look to start until later in the afternoon for northern Illinois and southern Wisconsin. The energy wave doesn't look to be particularly strong, as well as the low pressure but we still look to pick up some precipitation.
Temperatures with the southerly flow will warm into the low to mid 30's through Monday afternoon as rain spreads north through central and then northern Illinois. For northern Illinois however it will start will more of a rain snow mixture with temperatures hovering close to freezing. A light rain snow mix will continue late Monday afternoon into the evening. as temperatures overnight fall into the upper 20's this mix will then switch over to all snow. Light snow will continue overnight into early Tuesday morning. There is moisture available, but not much, so looking at this distance accumulations will be minimal if we get any at all.