Accumulating snow showers will continue over northeast Illinois Monday night, gradually shifting into northwest Indiana before ending later Tuesday night. A couple inches or more may fall in Lake and Cook Counties in Illinois tonight and early Tuesday, as an impulse associated with departing low pressure moves southeast out of Wisconsin. An inch or so additional snowfall may occur tonight in counties north of Interstate-80 and east of Interstate-39. West to northwest winds gusting over 20 mph will cause some blowing and drifting of snow, especially on north-south-oriented highways.
Lake-effect snow showers will likely shift into northwest Indiana Tuesday impacting Lake and Porter counties where additional accumulations may occur, especially in Porter County where a Winter Storm Watch remains in effect for Tuesday-Tuesday night.
Cold Arctic-source air will cycle into our area during the next 24 to 48 hours, compromised by the cloud cover and snow showers. Close-in areas including Chicago will probably experience wind chills near or just below zero Tuesday morning, while areas away from the lake, say the Fox River Valley west and south of Interstate-80 with less cloudiness will see wind chills on the order of -10 to -20-degrees late tonight and Tuesday morning.