Severe thunderstorms lingered throughout last week, the strongest of which affected the Valley Thursday night and Friday morning.

Obviously, the summer season is no stranger to severe thunderstorms with strong winds. One of the strongest types of storms typically occur during the summer months: derechos.

What is a derecho?

The definition of a derecho is important to understand before determining whether this week’s storms qualify. The word “derecho” is a Spanish word meaning “direct” or “straight ahead”.

A derecho is a superlative complex of thunderstorms that produce extremely high wind gusts over a large amount of time/space.

The qualifications for a derecho are as follows:

  1. Swath of wind extends over 400 miles
  2. Swath of wind is over 60 miles wide
  3. Includes wind gusts over 58 MPH over the majority of track
  4. Includes several wind gusts over 75 MPH for the majority of track

The midwestern United States is affected by a derecho once every year on average and that includes the Valley. The most likely place to experience a derecho is in the Ozarks of Arkansas, Missouri, and Oklahoma where they experience 4 derechos every 3 years.

Climatology of derechos in the United States. Image is courtesy of the Storm Prediction Center (SPC).

There have been two storm complexes in 2023 that qualified as derechos. One of them occurred in February and the other occurred in June. Neither of them affected the Valley. Did this week’s storms qualify?

Obviously, the storms on the morning of August 25th were powerful with heavy rain, strong winds, and even tornadoes. However, the storm complex was not strong enough to qualify as a derecho.

The thunderstorm did produce wind gusts in excess of 58 MPH over a 400 mile path and it the width of the path was over 60 miles. However, there were not enough wind gusts over 75 MPH to qualify. In fact, there was only one wind gusts of 75 MPH and it occurred at the Burke airport near Cleveland.

The complex of storms was still impressive as it produced a numerous damaging wind gusts from Michigan all the way to West Virginia. A map of all the wind gusts is shown below:

Wind damage reports from August 24-25.

Thankfully, this week of weather will be much for tranquil for the Valley.