Severe thunderstorms threaten to rake sections of the Chicago area Friday. The warmest temperatures here in two weeks this afternoon are to heat an atmosphere dripping with 2 inches of evaporated moisture, initiating the process of thunderstorm formation. Air rises and cools when that happens, especially when temperatures decline with height at a faster-than-usual rate. The atmosphere is labeled unstable by meteorologists in this situation. Add an unusually energetic jet stream with winds diverging overhead and the stage is set for atmospheric fireworks. That same roster of conditions late Thursday generated 52,000-foot-tall thunderstorms that bombarded north-central Iowa with golf-ball-size hail and wind-driven downpours. Weather watches may become necessary in the Chicago area later Friday and Friday night as the volatile situation unfolds.
Where are the 80s?
Thursday's official Chicago high fell just short of 80 degrees--hitting 79. There have only been 20 days with readings 80 degrees or warmer at O'Hare International Airport (31 is average). It's the lowest tally of 80-degree-or-higher days here in 35 years--since 1974 when July 10 arrived with only 19 days of 80s on the books.
Where are the 80s?
Thursday's official Chicago high fell just short of 80 degrees--hitting 79. There have only been 20 days with readings 80 degrees or warmer at O'Hare International Airport (31 is average). It's the lowest tally of 80-degree-or-higher days here in 35 years--since 1974 when July 10 arrived with only 19 days of 80s on the books.
