Why is it called a derecho?
Derechos (pronounced like “deh-REY-chos”) are fast-moving bands of thunderstorms with destructive winds. But instead of spiraling like a tornado or hurricane, the winds of a derecho move in straight lines. That’s where the storm gets its name; the word derecho means “straight ahead” in Spanish.
What caused the 2020 derecho?
It caused high winds and spawned an outbreak of weak tornadoes. Some areas reported torrential rain and large hail….August 2020 Midwest derecho.
| Flattened corn field near Adel, Iowa on evening of August 19, 2020. | |
|---|---|
| August 10 radar composite from 8am to 7pm CDT | |
| Tornadoes caused | 25 |
What is a derecho storm 2020?
According to the National Weather Service, a derecho is a long-lasting and widespread line of severe storms, associated with a band of rapidly moving showers or thunderstorms. On Aug. 10, 2020, the sustained line of storms affected eight midwestern states.
How rare is a derecho storm?
How often does a derecho occur? Midwest and southern plains states are most susceptible to a storm of this magnitude from April through August, but they aren’t very common. Depending on the area, a derecho has the potential to form once a year to once every four years, per the NWS.
What signals an approaching derecho?
Visually, an approaching derecho is often characterized by a bank of heavy shelf clouds (also known as arcus clouds), which are synonymous with this extreme weather event. These clouds have a distinct shape that is as awe-inspiring as it is ominous.
Where is a derecho most likely to happen?
Derechos in the United States most commonly occur along two axes. One extends along the “Corn Belt” from the upper Mississippi Valley southeast into the Ohio Valley, and the other from the southern Plains northeast into the mid Mississippi Valley (figure below).
How long can a derecho last?
about 10 to 20 minutes
Derecho winds typically last about 10 to 20 minutes at any one spot. In contrast, the 30- to 60-minute duration of severe gusts in the hardest-hit areas Aug. 10 was much more comparable to the passage of a hurricane eyewall than a tornado, whose winds typically last only a few seconds to a minute or two.
How wide was the derecho in Iowa?
The August derecho grew from a cluster of thunderstorms ranging from southeast South Dakota to Ohio. In its 14-hour span, it traveled east 770 miles across the Midwest, hitting Iowa the hardest with windspeeds of 100-plus miles per hour.
How do you spot a derecho?
By definition, if the wind damage swath extends more than 240 miles (about 400 kilometers) and includes wind gusts of at least 58 mph (93 km/h) or greater along most of its length, then the event may be classified as a derecho.