Snowfall depth forecasts have been downgraded for northern Cook County from 6"-8" to 4"-6". Most of Lake County and a small part of northeastern Cook County are in the forecast area for 6"-8". Most other regions are also downgraded, but snow is still expected.
URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE CHICAGO IL
905 PM CST THU FEB 23 2012
LAKE IL-DUPAGE-COOK-WILL-
INCLUDING THE CITIES OF...WAUKEGAN...WHEATON...CHICAGO...JOLIET
905 PM CST THU FEB 23 2012
...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 9 AM CST
FRIDAY...
With the precipitation of the present winter storm system already beginning, the precipitation has been mainly rain across the area. Temperatures are above freezing, and snow might not begin until about 6:00 p.m. That's the good news for rush hour commuters.
The bad news is that a Winter Storm Warning could still be activated later today or this evening. The area of heaviest snow could still shift south toward Interstate 88. The timing of freezing temperatures and heavy precipitation are a major factor. One thing is certain: The snow will be heavy and wet "Heart Attack Snow."