National Weather Service United States Department of Commerce


Storm approaching Tripp County image by Laura Welker


During the afternoon and evening of July 18, 2018, scattered strong to severe thunderstorms developed across western South Dakota. The most intense storm produced a brief tornado and significant straight-line wind damage over northeastern Tripp County, north of Hamill. Based on a storm damage survey, the highest winds of the tornado were estimated to be 90 to 100 mph, which gives it a rating of EF-1. In addition, straight-line winds snapped trees and power poles, with estimated wind speeds up to 115 mph. This storm is pictured to the left. Photo courtesy of Laura Welker from Hamill.

Farther west, a severe thunderstorm produced hail up to two inches in diameter and wind gusts to 70 mph across portions of Pennington, Custer, and Oglala Lakota Counties. The storm also produced locally heavy rainfall, which led to water over roadways across portions of Pennington County.


nws logo Media use of NWS Web News Stories is encouraged!
Please acknowledge the NWS as the source of any news information accessed from this site.
nws logo