We are in derecho season. I call this significant, long-lived, long-tracking, widespread wind events sometimes "County Fair Derechos" as we tend to get one during peak county fair time in July.
We tend to average one every year, when all data is averaged out:
Derecho occurrence is equal to that of the southern Plains here, overall, in May-August periods (see graphic). However, June-August sees the maximum occurrence in the general Corn Belt zone from Iowa & Minnesota to northwestern Ohio.
This number (according to Coniglio & Stensrud, 2004 with modification by SPC) refers to "the number of times moderate and high intensity derechos affected points in the United States during the years 1980 through 2001" in the May-August periods.
According to SPC this image is: "Approximate number of times "moderate and high intensity" (MH) derechos affected points in the United States during the years 1980 through 2001. Areas affected by 3 or more derecho events are shaded in yellow, orange, and red (modified from Coniglio and Stensrud 2004)."
A significant derecho, originating in eastern Nebraska, blasted through Iowa, Illinois, Indiana, Kentucky, Tennessee, North Carolina & northern South Carolina before diminishing on July 8, 2001.
Wind gusted to 69 mph at Fowler & Enos, 68 mph at the Purdue University Airport, 67 mph 3 miles south of Wolcott & 64 mph at Greentown. Gusts of 70 mph were reported in western Boone County. An embedded microburst produced an unconfirmed gust to 100 mph near Bunker Hill. Widespread wind damage occurred with trees & powerlines downed with some barn & roof damage in nearly every county. In Clymers (Cass County) a garage was blown off of its foundation & 5 homes were damaged. Windows were blown out of the Howard County courthouse. In Lafayette, a girl’s neck was broken when a tree fell on her car. A measured gust of 81 mph was recorded at the Anderson, Indiana municipal airport & a gust of 85 mph was recorded in southern Madison County with damage to a farm. Indianapolis International Airport measured a wind gust to 60 mph.
The derecho continued on to produce winds of 60-80 mph in southern Indiana & Kentucky. Even at Asheville, North Carolina a measured gust of 81 mph occurred as the derecho passed.
These are the July 8-9, 2001 (7 a.m.-7 a.m. Easter Time) storm reports. The serial derecho track shows up well!