The National Weather Service is warning of blizzard-like conditions late Tuesday night through Wednesday morning, with 8 inches of accumulation possible by the time it's all over.
A winter storm watch is in effect from 10 p.m. Tuesday to 1 p.m. Wednesday for Cook, Will, Lake, Porter, Jasper and Newton counties. The watch continued for LaPorte County until 5 p.m. Wednesday.
Rain is expected to change to snow Tuesday night as the cold front moves from north to south. Snowfall rates of 1 to 2 inches per hour are possible late Tuesday into early Wednesday.
Forecasters said the snow will be accompanied by 20 to 25 mph winds with gusts up to 40 mph, creating considerable blowing and drifting snow and blizzard-like conditions at times.
Travel conditions are expected to be treacherous. The National Weather Service anticipated travel at O'Hare International and Midway airports will be impacted Wednesday morning.