If a tornado flew straight instead of around and around, it would be a derecho. Derechos are storms that have sustaining winds that can be clocked at 100 miles per hour. The winds consistently have to reach at least 57 miles per hour to be categorized as a derecho. These storms can last for hundreds of miles and cause massive damage. Many times tornadoes will be present within and in front of the derecho storm system, but the derecho causes so much damage itself, that the tornadoes go unnoticed or cannot be confirmed.
The term derecho was first used in 1888 by Dr. Gustavus Hinrichs in the American Meteorological Journal. Derecho is derived from the Spanish word for straight. Hinrichs believed the word tornado came from the Spanish word tornar, which means to turn. Hinrichs was a physicist and chose the term to be cohesive with his beliefs of the origination of the word tornado.
A derecho takes the form of a long straight-lined windstorm that is shaped similar to a bow. There are three types of derechos: serial, progressive and hybrid. The serial derecho is formed from several bow shaped storms that forma a squall line and can extend for hundreds of miles and target a vast area. Progressive derechos typically only span from 40 to 250 miles and form a single bow shaped structure, they can travel over large distances. A hybrid derecho has characteristics of both a serial and progressive derecho.
In the United States, derechos are more probable in certain locations and at particular times of the year. May through August derechos are more common and most likely to form from the Mississippi Valley to the Great Lakes region or from the Mississippi Valley into the southern plains. September through April derechos rarely occur but if they do it is most likely to happen in eastern Texas and the south east states.
The damage from a derecho can be quite severe; the high winds are capable of rolling mobile homes and ripping the roofs off buildings. Tree limbs are ripped from their hosts and dropped on unsuspecting cars, buildings and, in the worst-case scenario, people. The derechos vicious wind can cause dangerous waves in lakes, capsizing boats. These storms are deadliest to those participating in outside activities or driving. Electrical outages are common and target a large area because of the immense size of the storm’s path, sometimes leaving hundreds to thousands of people powerless for a week or two.
Derecho is a term that does not have the popularity of its vortex like brethren, the tornado, but is just as dangerous and deadly due to its ability to rage on and on, covering a vast area and lasting for hours.
