During the early afternoon hours of Friday, June 29th, thunderstorms developed near Chicago and quickly intensified as they moved into northern
Indiana. Producing a wind gust to 91 MPH in Fort Wayne, Indiana, the storms matured into a derecho as they entered the NWS Wilmington OH
forecast area. Over the next few hours, the derecho produced widespread significant wind damage across the majority of NWS Wilmington's forecast
area, with measured wind gusts over 80 MPH in a few locations. The derecho moved quickly across the area (which is typical and helps to
push the high winds out ahead of the system), entering the northwest corner of the area around 3:15 PM and exiting the southeast by 7:00 PM, with
an average forward speed in excess of 60 MPH. During the event, NWS Wilmington OH issued 19 Severe Thunderstorm Warnings.
What is a Derecho?
Derecho (pronounced "deh-REY-cho") is a Spanish word that means "straight." In meteorology, the term is used to describe a long-lived,
violent straight-line convective wind storm. A derecho usually takes the form of a squall line or large bow echo, travelling hundreds of miles.
Derechos produce widespread wind gusts to severe criteria (50 knots or 58 MPH), and wind gusts to 80 MPH (even 100 MPH in rare cases) are possible.
Derechos are not very common, as many atmospheric conditions have to come together perfectly for one to form. The extreme winds caused by derechos
are sometimes mistaken for tornadoes due to their violent and turbulent nature, the appearance of swirling wind vortices sometimes observed along
the leading edge of the gust front, and the significant amount of damage they cause.