Chicago First Alert Weather: Rain And Snow On The Way; Winter Storm Watch Begins Early Thursday

CHICAGO (CBS) -- After a chilly morning, Tuesday's temperatures climb with highs near 40 degrees. The bigger concern becomes a rain/snow event late Wednesday and into Thursday.

A Winter Storm Watch has been issued for most the Chicago area - including Cook, DuPage, Kane, Will, Kendall, DeKalb, Kankakee, and LaSalle counties in Illinois, and Lake, Porter, Jasper, and Newton counties in Indiana. The Winter Storm watch begins at 3 a.m. Thursday and continues until 9 p.m. Thursday.

A Winter Storm Watch is also in effect from 10 a.m. to 10 p.m. Thursday for LaPorte County, Indiana.

A strong south wind will boost temperatures into the low to mid 40s for Wednesday morning, then low 50s in the afternoon.

Rain chances increase in the afternoon on Wednesday, then showers will be likely Wednesday evening. That rain will be heavy at times overnight.

Rain transitions into sleet and freezing rain by early Thursday morning. The icy mix then changes to snow area wide. Ice and snow accumulations are likely. The models for snow accumulation vary widely at the moment, meaning snow total predictions at this point are difficult.

Friday starts off very cold, lows in the single digits and only reach the middle 20s underneath a sunny sky.