Beyond The Forecast - The deadly storm that hit Houston determined to be a “derecho”

A derecho is a widespread wind storm

Recapping the derecho that hit Houston, Texas last Thursday

ROANOKE, Va. – Good Monday morning, and welcome to another edition of Beyond The Forecast.

This week’s newsletter is a bit more somber, as it pertains to the deadly storm that hit Houston this past week.

The storm killed seven people Thursday night. As of Sunday afternoon, more than a quarter-of-a-million people remain without power in and around Houston.

Initial reports indicate that the storm produced gusts of 90 to 100 mph in Houston. There were also a pair of EF-1 tornadoes that happened during this time.

After collaboration between the National Weather Service and Storm Prediction Center, the storm was ruled a derecho.

For readers in Southwest Virginia, we became well acquainted with that weather term in late June of 2012.

Derecho criteria means the storm produces damage along a swath of at least 240 miles.

A derecho has to produce wind damage along a path length of at least 240 miles.

Looking at storm reports from last Thursday, you can see that clearly happened as the cluster moved from West Texas to the Florida Panhandle.

Damage reports from Thursday's derecho that moved from Texas to Florida.

This is a part of the country in which derechos are fairly infrequent. The Storm Prediction Center says they happen about once every four years in areas like Houston, Texas.

Derechos happen on average once every four years in areas shaded in green, according to the Storm Prediction Center.

They’re most common farther north, specifically in the upper Midwest.

Especially in the summer months, you’ll find these wind storms form on the northern edge of a heat dome, riding a temperature boundary until it loses its energy and dissipates.

So long as there is heat to the east and rain-cooled air behind the bowing storm, it can keep chugging along for miles and miles.

How is it that derechos can travel such long distances?

You can always get specific forecast details for your zone, whether it’s the Roanoke Valley, the Lynchburg area, the New River Valley, Southside or the Highlands anytime at WSLS.com/weather. Know your zone!

In case you missed it, we have other great weather and science content on WSLS.com as well.

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