6/24/2013 - Northern Illinois Derecho

Another summer day in northern Illinois -- another convective system.  In this case, a derecho-producing convective system developed near the Quad Cities and raced eastward at speeds near 60-70 mph, generating a swath of damaging winds 100s of miles long.  I intercepted the storm along I-88, just east of Dixon. I originally stopped in Dixon to await the storm, but became concerned I would not have enough time to get on the oddly configured I-88 entrance ramp in time as the storm approached. Therefore, I made the decision to hop on the toll and find a spot to pull over on the interstate. Luckily, shoulder work was occurring in a few spots. I picked one of those construction sites and watched this beast of a storm approach about as quick as any storm I've ever witnessed (this was likely faster than the 4 August 2008 derecho-producing convective system).  Because of the speed of the storm, it didn't have the typical anvil overspread providing shade. This produced a horrible lighting situation, which had me peering to the southwest looking for a probable tornado-producing mesovortex. Indeed, a tornado to my immediate southwest was confirmed later by the NWS -- I wonder if many of these line mesovortex tornadoes have condensation to the ground? Doubt it.  As soon as I could make out the mesovortex, it was on me. I raced east on I-88, never stopping until I got off the DeKalb exit. Amazingly, the storm was still on me as I exited, permitting only about 30 seconds of pictures before it began to rain. I guesstimate the storm speed along this micro-surge due to the mesovortex was near 75 mph, if not greater. Not the best photography day, but a heck of a storm to experience.

View out the sunroof along I-88 as I tried to stay ahead of the beast.

View of "wall of water" at Huntley Middle School in south DeKalb.

Lapse of wide-angle scenes east of Dixon and south of DeKalb.