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Derecho AND Tornado in One Day! | August 11th, 2026 Storm Observation Summary

I'm not sure how many more times I can say "man, what a day" in 2026. The whole year has become hyperbolic at this point when it comes to significant severe storms in the Midwest, and more specifically my home state of Illinois.


Guidance the night before hinted that Tuesday, August 11th could be a rather volatile day across Illinois and Indiana with a potential 1-2 combination of a morning storm cluster producing significant severe weather with a second afternoon storm risk that could feature supercells on the residual outflow boundary. It had the potential to be a literal very long day.


I woke up at 4 AM to get the local forecast out including some additional guidance on the severe weather risk locally later that day, and then sent out my usual public and private communications regarding the broader risk across the region. I was out the door around 10 AM, blasting north on Interstate 57 to get into the path of a rapidly intensifying bow echo racing out of Iowa.


There was no real shelf cloud or time to enjoy an incoming-storm scene as the derecho approached the I-57 corridor as storms erupted out ahead of the line, obscuring any storm features. The situation began to escalate quickly on my as I approached Peotone, so as much as I'd hoped to get 5-10 miles further north I decided this was where I would ride the storm out.



I estimated 80+ mph winds in my report to the National Weather Service and later saw a gust measured at 87 mph by a weather station in Peotone validating my estimate. Widespread tree damage and power outages were noted as I exited Peotone and made my way north where an apparent tornado had occurred based on radar imagery.


I traced a tornado damage path from Monee to Crete over toward the Indiana border but called off the damage survey there as it became increasingly difficult to get through anywhere due to roads being blocked by downed trees and powerlines.


This was also about the time I noticed that the outflow boundary from this morning cluster of storms had settled right along Interstate 74, very close to home in Champaign-Urbana. There was also an area of convection percolating and heading southeast toward the boundary near the Peoria area. Pattern recognition and a little arithmetic said this storm would be hitting that boundary around 3-4 PM right as the volatile air mass primed across the area. It was like 90 degrees near Champaign-Urbana with a dew point of 78, something like 5000 j/kg of mlcape and parameters off the charts centered over home base with an outflow boundary running right through it.


After doing a quick interview with WBBM in Chicago about the storms I grabbed a sandwich and a fountain coke and began my journey back south on Interstate 57 for this potential second round. I gassed up in some rain and thunder in Rantoul and headed west on Hwy 136 out of town toward the intensifying storm. As I zig-zagged southwest into the path of the storm it rapidly intensified, and as I approached from the west on Highway 10 I became very certain that it was about to produce a tornado. This was mostly based on radar and velocity signature at the time, but I noted on video "there's something big crossing the road ahead of me" and did indeed confirm later on that the tornado damage path crossed Highway 10 just up the road to my west.


I took a south on a rural road and spotted the tornado about 2 miles south of Seymour, the tornado likely would have been crossing Interstate 72 at this time where a truck was blown over. The tornado traveled quickly southeast, being pushed by the surging RFD visible as a low contrast slender cone and then eventually a broader rotating bowl funnel that at times appeared to have multiple smaller circulations within it.


This was a tough tornado to document for a few reasons. I kind of thought I'd have a chance to setup and tripod this storm for a bit, but it ended up accelerating southeast as it grabbed the boundary and went off. I'd guess the tornado was moving 45-55 mph or so, which is one thing if it's going straight north, south, east or west and you can just drive along with it, but with a southeasterly motion I had to zig-zag east, then south, then east, then south. There was no way I'd keep up, especially as increasingly strong northerly winds and rain began to overtake me while worrying about my own situational awareness and safety during a rapidly changing storm.


Additionally, chasing solo and following a confirmed tornado into my stomping grounds meant I needed to put documentation as a secondary priority while I prioritized reporting the tornado to the National Weather Service and then getting on the air with WILL/Illinois Public Media.



Wild scene as the tornado continued south and then southeast away from me, and I drifted with the storm as it flattened corn with widespread downburst winds over 70 mph.


I broke off the chase in northern Douglas County as it became more apparent the storm would not be producing another tornado and continued to prove to be a challenge to keep up with. I'd certainly had my fill for one day, anyway. Pretty hard to top a derecho PLUS a tornado.


I made the day longer still by retracing the path of the circulation and locating the path of the tornado with my drone, visible as a convergent path through the corn, also impacting several farms and as mentioned earlier blowing over a truck on Interstate 72.


I'll have a longer storm observation VLOG from the entire day soon, but for now enjoy the shorter clips from the two storm intercepts linked above while I take a final summer vacation with the family up north this weekend.

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