A cold rain expected elsewhere in the immediate Chicago area but untreated roads and sidewalks could be slippery for a while this morning
A Winter Weather Advisory remains in effect for Lake and McHenry counties in Illinois . The center of a low pressure system is expected to move out of south-central Iowa through central Illinois into northern Indiana by this evening. Ahead of the low temperatures across most of northern Illinois early this morning were in the lower and middle 30s and precipitation was mostly rain, with scattered areas of freezing rain mainly west and north of the city . At the morning commute in the Chicago area there could still be a few spots where freezing rain could mix with sleet, but for the most part the should experience a cold rain. Farther north - closer to the Illlinois-Wisconsin state line, there is a better chance of the mixed freezing rain/sleet/snow combination. The threat of icing should diminish as the morning wears on and temperatures creep into the middle 30s.
Snow to develop across the area from north to south later today
As colder air arrives in the area later today, the rain will change to snow first in areas along the Wisconsin state line this afternoon then spreading south into the city and the remainder of the Chicago Metro area late this afternoon and evening. The snow could become heavy for a few hours with accumulations ranging from 2-4 inches close to Wisconsin, tapering off to an inch of less south of the city. Heavier snow amounts of 3 to 6 inches are possible in southeast Wisconsin.
Below is the Winter Weather Advisory issued by the Chicago National Weather Service Office this morning and a map depicting the two Illinois counties under the advisory.
Winter Weather Advisory
NATIONAL WEATHER SERVICE CHICAGO IL 413 AM CST THU FEB 7 2013 ...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 4 PM THIS AFTERNOON TO 9 PM CST THIS EVENING IN LAKE AND MCHENRY COUNTIES INCLUDING THE CITIES OF WOODSTOCK AND WAUKEGAN * TIMING...ACCUMULATING WINTRY PRECIPITATION IS POSSIBLE AS EARLY AS LATE THIS AFTERNOON...BUT MORE LIKELY THIS EVENING. * PRECIPITATION...SOME LIGHT SLEET...SNOW...OR POSSIBLY A TOUCH OF FREEZING RAIN IS POSSIBLE EARLY THIS MORNING...BEFORE TEMPERATURES RISE ABOVE FREEZING CHANGING THE PRECIPITATION TO ALL RAIN. WITH TEMPERATURES NEAR OR JUST ABOVE FREEZING THE CHANCE OF ANY APPRECIABLE ACCUMULATION EARLY THIS MORNING APPEARS LOW. RAIN IS EXPECTED TO MIX WITH AND CHANGE OVER TO WET SNOW LATE THIS AFTERNOON OR EVENING. A PERIOD OF MODERATE SNOW IS POSSIBLE THIS EVENING WITH SOME SNOW ACCUMULATION EXPECTED AT THAT TIME. * ACCUMULATION...SNOW ACCUMULATIONS OF 1 TO 3 INCHES ARE POSSIBLE THIS EVENING