Wednesday’s mixed sunshine comes just a day after the area’s far western suburbs were hit with 2”+ rains—the biggest in over 7 weeks. It may literally be the calm before the storm. Computer models project a rapidly intensifying low pressure system is to assemble over the Plains. Air drawn aloft into a powerful jet stream leads to strengthening southerly winds which by Thursday are to be stacked vertically tens of thousands of feet through the atmosphere above Chicago. The howling flow—whistling through Chicago airspace at 60+ m.p.h. only 2,000 ft. above ground—sweeps 70°+ warmth and moist 65°+ dew point air into the area and is likely to feed waves of showers and t-storms. It’s beyond that point at which there is the greatest concern for severe weather.
Only 12% of the tornadoes and severe t-storms here since 1950 have occurred in autumn months. Thursday’s weather will have to be monitored.
--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.
