What Is A Derecho? (Hint: Highly Destructive Force Of Nature)

What Is A Derecho? (Hint: Highly Destructive Force Of Nature)

You’re in the middle of a midwestern field right now. You feel a warm breeze gathering. Then wall of clouds starts heading in your direction. The wind gets stronger. Then a thunderstorm comes out of nowhere.

Amazingly, the wind gets even stronger. So strong that it damages a barn in a neighbouring field. These aren’t the soft and fluffy clouds of fairy tales. Ladies and gentleman, it’s derecho season.

A Derecho is a storm…

Derecho’s get their name from the Mexican word for “straight” because of the beeline path the combination wind/thunderstorm takes. They most frequently arrive in the US beginning in late June and occur all the way through July. And a derecho will strike night or day – they don’t discriminate.

…that occurs primarily in the central United States…

Derechos in the US generally occur through out the southern Plains, the Mississippi Valley, and the Ohio Valley. Derechos have also been known to occur in Brazil, Argentina, Canada and even Germany.

…has the power to crumple buildings…

Derecho’s can reach speeds up to 210km/h and are at least 385km long. They can also travel hundreds of kilometres in a given direction. Most recently, a derecho struck in Marshalltown, Iowa, where it battered down the top of a grain silo (see above). That same derecho also moved through Indiana, Illinois and Ohio, with winds reaching speeds up to 128km/h. Barns and mobile homes are frequent structural victims of derecho storms.

…was first documented 134 years ago…

The derecho was first documented in Iowa City by chemist and physical scientist Gustavus Hinrichs on July 31, 1877, though he did not formally use the term until 1883.

…and plays nice with other threatening weather systems.

In case you’re wondering, derechos and tornadoes can happen at the same time for double the disaster. There are even “super derechos” which can cause damage independent from the main wall of clouds. [NOAA and Mike Borland via Matt Hardigree]

Image courtesy of Mike Borland