A major early season winter storm will bring heavy snowfall to portions of the area today through tonight. During the height of the storm across northern Illinois this evening into the overnight, snowfall rates of 1-2 inches or more per hour will be likely along with very strong northerly winds gusting up to 40-45 mph, and likely higher near Lake Michigan. During this time, blizzard-like conditions will be possible, which will cause dangerous and even life-threatening travel conditions. Furthermore, the heavy wet snow and wind may down tree limbs onto power lines, causing power outages.
Areas southeast of I-55 and into northwest Indiana will be latest to transition to snow this evening into tonight, but can still expect a period of adverse winter weather into Monday morning.
Impacts to the Monday morning commute are now likely over northeast Illinois and northwest Indiana due to an overall slower progression of the winter storm.