Thunderstorms are already building over Lake Michigan and showing signs of back building. A single thunderstorm cell developed just west of Arlington Heights and was moving very slowly toward the northeast about 9:30 a.m. Thunder has been rumbling for more than an hour as the storm approaches. Significant rain did not begin until about 1:00 a.m. and stopped by 2:00 a.m. with about 2.2 inches of rain reported at Chicago Executive Airport.
A severe thunderstorm was issued for DuPage and Cook counties overnight.
As of 1 a.m., the monthly rainfall total recorded at O’Hare International Airport stood at 10.45 inches — already the wettest July on record. We’re expecting an additional 2 inches to be added from the overnight rainfall Thursday to Friday. Before July 2011, the previous July rainfall record was 9.56 inches, set in 1889. The overnight rainfall also ranked this July the eighth wettest month ever in Chicago.
The all-time wettest month in Chicago was reported in August 1987, when 17.1 inches of rain came down. During that month on August 14, 1987, a record 6.49 inches of rain was reported. That record has since broken on September 13, 2008 (6.64 inches) and July 23, 2011 (6.91 inches).
Become a fan of The Cardinal weather page. Submit your pictures or just stay up-to-date on weather topics — go direct to the Arlington Cardinal Weather photos. For a list of all of The Cardinal Facebook fan pages, go to Arlingtoncardinal.com/about/facebook …