Thursday dawns with lake-effect clouds still generating snow showers and flurries over parts of the area. But, the atmospheric set-up responsible for the snowfall is to break down. Temps aloft are beginning to warm—a development which in time is to extinguish the upwelling of air critical to lake snow formation. In addition, surface winds are to change direction. Instead of blowing from the NE, a trajectory which brings them over 90-plus miles of open lake water, the flow will become SE this afternoon and evening. This dramatically reduces the air’s contact with water, shutting down the lake snow’s moisture supply.
More than 2” had fallen by late Wednesday evening at Schererville, Ind., and Beach Park (near Waukegan), while just 0.8” fell at Midway. Spotty accumulations in excess of 4” are likely in the hardest hit areas close to the lake.
Out East, hard-hit Boston recorded another 4.5” Wednesday bringing its January total to 42.2”—the greatest amount ever observed there for the month.
WGN-TV Chief Meteorologist Tom Skilling and the WGN Weather Center staff provide daily coverage of weather in the Chicago area.
