July 24, 2009 hailstorm in northwest Illinois

Dear Tom,
On the evening of July 24, 2009, I was in Apple River Canyon in northwest Illinois and we had a tremendous hail storm. The entire tri-state area was hit by severe storms. Do you have details?

—Terri Grommes, Batavia

Dear Terri,
Severe thunderstorms lashed northwest Illinois, eastern Iowa and southwest Wisconsin for almost four hours that evening. Winds were as high as 90 mph and much of the hail was between golf-ball and tennis-ball size. The hail devastated area crops, stripped leaves off trees, broke windows, dented autos and damaged roofs and siding. Power in the area was out for hours. The largest hailstone —2.5 inches in diameter—was reported at Stockton, Ill. Heavy rain produced flash flooding in the Sterling area causing some roads to be closed.

Severe Thunderstorm Watch issued for portions of the Chicago area

A Severe Thunderstorm Watch has been issued until 4AM Wednesday for a large portion of northeast Illinois, including the City of Chicago. 

This watch includes the following counties:  Cook, Lake, McHenry, Du Page, Kane, DeKalb, Kendall, La Salle, Boone, Winnebago, Lee and Ogle. 

Below:  Severe Weather Watch #60 with current radar

WW0060 Initial Radar image

Thunderstorms may not arrive until well after Midnight

Most of the Chicago area should remain storm-free through the rest of the evening.  A cold front will begin to approach after midnight sparking an increase in thunderstorm activity.  Despite the loss of daytime heating and the return of a lake wind, there is still potential for strong to severe thunderstorms due to potent upper level dynamics

The Storm Prediction Center may issue a new Severe Thunderstorm Watch for portions of northern Illinois by 10PM.