Derecho blows through Kansas, Oklahoma, and Arkansas on June 22
A line of severe thunderstorms that developed in northwest Kansas on June 22 and tracked across the state into Oklahoma and into central Arkansas, has been classified as a derecho, according to the National Weather Service in Norman, Oklahoma.
The derecho spanned 500 miles with a total damaging wind path of 700 miles. In Oklahoma alone, the winds swept across 400 miles from west to east, providing much-needed moisture, but also causing wind damage and leaving many without electricity.
The derecho brought hurricane-force gusts of 70 to 80 miles per hour, peaking at a 102 mph in Hinton, Oklahoma, according to the Oklahoma Mesonet.
In addition to the straight-line winds, several tornadoes touched down in Kansas and Oklahoma during the storms. An EF2 tornado killed one person on Sedgwick County, Kansas. Tornadoes were also confirmed to have touched down in the Oklahoma cities of El Reno, Harrah and Wetumka.
In between the Oklahoma towns of Woodward and Mooreland, at least 80 intermodal well cars from a BNSF train were blown over due to the strong winds, spilling approximately 160 containers. Structures, homes, trees, and crops, such as corn, were also damaged.
Defining a derecho
A derecho is a widespread, long-lived windstorm associated with a rapidly moving band of showers or thunderstorms. While the damage can resemble that caused by tornadoes, derecho damage typically follows a relatively straight path, leading meteorologists to describe it as straight-line wind damage.
The term “derecho” was introduced in 1888 by Gustavus Hinrichs, a physics professor at the University of Iowa. Hinrichs used the Spanish word, meaning “straight,” to distinguish thunderstorm-generated straight-line winds from the rotating winds associated with tornadoes.
According to the NWS, a storm system may be classified as a derecho when its wind damage extends more than 240 to 250 miles and includes wind gusts of at least 58 mph along most of its path, along with several stronger gusts.
Derechos occur throughout the year. but are most common during the warmer months when hot, humid conditions help fuel severe thunderstorm development. The NWS estimates about 70% of U.S. derechos occur between May and August.
Meteorologists say derecho formation is closely tied to bow echoes, which are curved lines of thunderstorms visible on weather radar. These systems develop when rain-cooled air from thunderstorms spread outward and force warm, moist air upward along a gust front, creating new storms and strengthening the overall system.
Although these storms are not common, according to the NWS, the central U.S. is the most active region for derechos. Meteorologists note that derechos can be difficult to predict because they often develop in environments where subtle atmospheric disturbances can trigger strong and rapidly formed thunderstorms. Once established, the systems can travel hundreds of miles in a matter of hours, which is what occurred June 22.
Lacey Vilhauer can be reached at 620-227-1871 or [email protected].
