CHICAGO (CBS) -- A frost advisory is in effect Tuesday night for DeKalb and LaSalle counties.

Lake effect showers tonight in Northwest Indiana, meanwhile it'll be mostly clear in DeKalb and La Salle County with frost possible. Lows will be in the low to mid 40s in Chicago and partly cloudy.

Shower chances continue for Northwest Indiana for Wednesday, but mainly in the morning hours. A couple of showers may drift into Chicago by late-morning. Partly cloudy and cool for Wednesday with highs in the upper 50s.

Mostly sunny to sunny and warming late this week into the weekend. Highs will be in the 60s Thursday & Friday, then near 70 degrees this weekend.

TONIGHT: Partly cloudy and chilly. Shower chance in Northwest Indiana. Frost possible in the far west. Low 44°

WEDNESDAY: Scattered showers for Northwest Indiana, isolated showers for Cook County. Otherwise, partly cloudy and cool. High 59°

THURSDAY: Mostly sunny. High 64°