The most humid air in a year erupted into thunderstorms for the third time Monday blasting sections of the Chicago area with 40 mph gusts, prodigious cloud-to-ground lightning and rains of up to 4”. Even before Monday’s rains hit, Chicago’s Aug. 1-6 rainfall (1.46”) ranked the 19th heaviest for the period since records began 136 years ago. Blinding rains and, at one point Monday evening more than 3,000 cloud-to-ground strokes in 10 minutes, walloped some south and western suburbs. Western DeKalb County—7 miles southwest of DeKalb—proved ground zero for the heaviest storms. There 3.82” of rain fell between 3:50 p.m. and 6:50 pm—2.90” of it in just 30 minutes.
Blistering heat downstate—this summer’s hottest yet—provided the fuel for the storms. Temps topped out near the century mark at St. Louis (99°), 99° at Centralia and 100° at Mt. Vernon. The heat index at Taylorville reached a staggering 113°.
-By Tom Skilling, WGN-TV Chief Meteorologist
