Cooler air moved into the Chicago area Friday on gusty north winds that brought lake-effect rain showers to east and south portions of the city and portions of northwest Indiana. Afternoon highs peaked only in the middle and upper 50s, the area’s chilliest highs since May. The arrival of the cold air has also set the stage for the first widespread frost and freeze event of the season, with only areas in the heart of the city and near the lakefront likely to be spared. The chill won’t last long, however, as readings are expected to rebound into the 60s both Sunday and Monday afternoon and then surge into lower and middle 70s on Tuesday and Wednesday. The warmer weather will also bring an increase in moisture to the region, raising prospects for a chance of much-needed showers and thunderstorms to the area straddling the period from late Tuesday through early Wednesday as a cold front moves through the area.