In early June 2020, a rare derecho event swept through the Rockies and the Plains, including Utah, Colorado, Wyoming, and North and South Dakota.
The derecho caused widespread damage in South Dakota. Sections of Interstate 90, which runs from east to west through the middle of the state, needed to be closed temporarily to deal with construction site damage and vehicle rollovers. Additionally, the derecho spawned at least two tornadoes in South Dakota.
The NOAA Unique Combined Atmospheric Processing System (NUCAPS) showed “pronounced instability” in the atmosphere when Suomi NPP overflew South Dakota the afternoon of June 6. NUCAPS uses Cross-track Infrared Sounder (CrIS) and Advanced Technology Microwave Sounder (ATMS) instrument data from Suomi NPP and NOAA-20 to create profiles of temperature, moisture and other factors in the atmosphere. This helps forecasters predict and warn the public about severe weather.
According to the National Weather Service Weather Forecast Office in Rapid City, South Dakota, “Derechos are characterized by a several hundred mile long swath of persistent severe wind gusts (58 miles per hour or greater), with embedded wind gusts that are considered significantly severe (75 miles per hour or greater).”