After an evening of warnings to prepare for what was expected to be one of the worst storms in the last 70 years, the system moved in overnight, intensifying near the start of rush hour. The storm started with moderate winds and gusts overnight, with the light rain moving in prior to a squall line forming and tearing through Chicago. There are unconfirmed reports of tornado's in Will County and possibly Kane County as well as Wisconsin and along the Illinois/Indiana border.
O'Hare International Airport (ORD) experienced a complete ground stop of both departing and arriving flights and, once operations resumed, most airplanes were still unable to land. Winds at one point were reported from the southwest at 50mph sustained, gusting to over 65 mph. This resulted in planes diverting to other area airports such as Madison (MSN), where the winds were more favorable and better aligned with the operating runways. If planning any flights on airlines today, please check with your carrier as the delays, cancellations and diversions can effect operations across the country resulting in significant delays or additional cancellations.
At DuPage County Airport (DPA) in West Chicago, the storm destroyed 3 airplanes as it passed through.
For full story and details, see my Chicago General Aviation article.