CHICAGO (CBS) -- Partly cloudy skies and not as cold tonight. Lows in the upper teens and low 20s, with wind chills in the single digits and low teens.

Morning sunshine, then turning partly cloudy in the afternoon as a cold front moves in Thursday mid-afternoon. Highs will occur in the early afternoon at around 30 degrees.

Temperatures will dramatically drop Thursday evening with wind chills in the teens. Low temperatures by Friday morning will be just above zero degrees, but wind chills could be as cold as -20 to -25 degrees.

Friday will be mostly sunny, breezy and very cold. Single digits in the morning and only in the low teens in the afternoon. Wind chills Friday afternoon will be near zero degrees.

A southerly wind will boost highs back above freezing for Saturday afternoon, then to the 40s by Sunday. Above average highs in the upper 30s and low 40s are expected into next workweek.

TONIGHT: Partly cloudy skies. Low 18°, with wind chills between 3 and 10 degrees.

THURSDAY: Morning sun, then afternoon clouds. Turning colder by the mid-afternoon. High 30°, with wind chills in the upper teens and low 20s.

FRIDAY: Mostly sunny, breezy and much colder. High 12° with wind chills around zero in the afternoon.