MEASUREMENTS OF HEAVIER CHICAGO RAINFALLS OUT OF TUESDAY EVENING’S THUNDERY, WINDY AND LIGHTNING PUNCTUATED DOWNPOURS–PLUS DRAMATIC VIEWS OF ONE OF THE STORMS SWEEPING INTO THE CRYSTAL LAKE AREA . 

Warm season rains are notoriously unevenly distributed–with dramatic downpours hitting one area while many others receive NOT A DROP. That sort of precipitation disparity was on display in spades with Tuesday evening’s eye-catching often windy and downpour generating storms. Their lightning was a sight to see. Yet we will hear from many who received not a single drop. Thunderstorm outbreaks often do that.

Modeling, which didn’t handle Tuesday’s storm well, had suggested storms might impact just 20% of the Greater Chicago area. Tuesday’s rain may have been a bit more extensive than that—but the storms were still selective in the areas they hit.

As the graphics included with this post show, and a break-out of the heavier COCRAHS volunteer observer reports by my WGN meteorological colleague Mark Carroll indicate—there was a wide range in the rains which occurred:

  • IIL-MCH-83 Crystal Lake 1.0 WSW 0.27
  • IL-CK-75 Elk Grove Village 2.2 WSW 0.24
  • IL-CK-326 Morton Grove 1.2 WNW 0.24
  • IL-CK-374 Glenview 1.3 WNW 0.24
  • IL-KN-23 Batavia 1.5 WNW 0.23
  • IL-CK-94 Lincolnwood 1.8 E 0.22
  • IL-MCH-49 Cary 0.3 NE 0.22
  • IL-MCH-9 Algonquin 2.1 W 0.20
  • IL-KN-135 Batavia 0.8 W 0.19