Winter storm Warnings are in effect from the southern Rockies through the central plains into the western Great Lakes. Several feet of snow is forecast for the mountains of Utah and Colorado today with up to a foot of snow/blowing and drifting snow from sections of Nebraska across northern Iowa/southern Minnesota into Wisconsin and Upper Michigan later tonight through Tuesday/Tuesday night (see highlighted areas on map above – pink-shaded depicted Winter Storm Warning for heavy snow and red-shaded areas depict Blizzard conditions with near zero visibility at times).
Tuesday the Chicago area will transition from the unseasonably mild rain/thunderstorm area in our southern portions to possibly 1 to 3-inches of snow accumulation in our northern counties along the Illinois-Wisconsin state line Tuesday morning. By midday Tuesday, most of the Chicago area looks to be in milder air/rain. Across southern Wisconsin 4 to 6-inches of snow may fall Tuesday, while to our south all the way from the Gulf of Mexico into southern/central Illinois/Indiana will be under a threat of severe thunderstorms.
A center of low pressure is expected to assemble over the southern Rockies, coming together into a single storm center over eastern Kansas early Tuesday – then following a northeast track from near Kansas City to Chicago by evening and on into northern Lower Michigan Tuesday night. Strong northwest winds on the backside of the departing low pressure will pull much colder air into our area later Tuesday night/Wednesday with some light snow showers or flurries possible.