Heat heads this way; surging humidities to brew storms
For many, Tuesday’s temperature-slashing NE winds arrived not a moment too soon. Tuesday’s 83° was 12° below Monday’s steamy 95° thermometer reading. But, an even more impressive plunge in atmospheric moisture levels—clear in the dramatic dew point pullback from Monday’s 76° to late Tuesday’s 56°—really hit home for most area residents. The air here, from which 2” of evaporated moisture could have been squeezed Monday, held just 0.72” late Tuesday—only 35% as much! While downstate Illinois residents retired late Tuesday amid muggy 80° dew points and 90° evening temperatures, heat indexes threatened to surge into the dangerous 105-115° range Wednesday. By contrast, Chicago area residents were able to open windows Tuesday night and enjoy more normal nighttime cooling. Drier air retains less heat. But surging moisture Wednesday night threatens new t-storm clusters.
-Tom Skilling