On January 11, 2022, the National Oceanic and Atmospheric Administration and Environment and Climate Change Canada formally revised the criteria for a storm to be classified as a derecho. A wind storm must meet the following criteria:
Wind damage swath extending for more than 400 miles (640 km)
Wind gusts of at least 58 miles per hour (26 m/s; 50 kn) along most of its length
Several, well-separated 75 miles per hour (34 m/s; 65 kn) or greater gusts
Prior to January 11, 2022, the definition for a derecho was:
Wind damage swath extending for more than 240 mi (390 km)
Wind gusts of at least 58 mph (93 km/h; 26 m/s; 50 kn) along most of its length
If ya’ get a real “doosey” with a strong bookend vortex, the 75+ mph wind gusts may be nearly continuous over a long path. We got that in the May 9, 2009 “super derecho”.
If you were in the worst of it, or did cleanup / repair work afterward along that path, esp. the track through SEMO and S. IL, you DON’T doubt the term “super derecho”. That MCV (Mesoscale Convective Vortex) or “bookend vortex” on the north end of that derecho was a real mo-fo.
Interestingly, THIS storm has been showing a large MCV on radar. It appears two large storms have merged and the north end developed the MCV. However, this MCV is both larger and less defined than one in the 2009 storm, and the whole thing seems to be weakening, thankfully.