Potentially dangerous thunderstorms threaten for the second time in three days. Milder, more humid air in the “warm sector” of a powerful early spring storm has rushed into Chicago on SW winds overnight in the wake of a warm frontal passage. Of concern to forecasters is the rapid descent of temperatures with height, converging winds along an incoming cold front and diverging winds aloft—an indication air is rising on a broad scale. This atmospheric combo encourages thunderstorm growth. Shifting wind direction with height causes such storms to rotate—much as the t-storm cell responsible for Saturday night’s devastating Carol Stream microburst did before sending a powerful blast of air through the west suburban community.
The unseasonable chill which plunges over most of the Lower 48 east of the Rockies in coming days threatens Chicago with its coldest early April outbreak since 1996.
--By Tom Skilling, WGN-TV Chief Meteorologist
WGN-TV Chief Meteorologist Tom Skilling and the WGN Weather Center staff provide daily coverage of weather in the Chicago area.
