Low pressure moving east up the Ohio River Valley will spread cloudiness and a wintry mix of precipitation across at least the southern portion of the Chicago area Friday night. The developing situation will have to be watched very carefully—with borderline temperatures at the surface and aloft, the shield of precipitation could comprise of rain, sleet, wet snow or even patchy freezing rain, focusing primarily on the area along and south of Interstate-80. Travel south and even west out of Chicago could become very hazardous.
Improving conditions are expected St. Patrick’s Day, as the low pressure draws away from our area. Northeast winds on the backside of the departing low pressure will most likely still keep readings in the 30s along the lakefront, while inland temperatures should work their way into the 40s.