Sioux Falls, South Dakota – Residents across eastern and central South Dakota should prepare for a potentially active afternoon and evening as severe thunderstorms develop with the threat of damaging wind gusts, large hail, and torrential rainfall. The greatest impacts are expected between 2 p.m. and 11 p.m., when storms could rapidly intensify and move southeast across the region.
According to the National Weather Service in Sioux Falls, thunderstorms are expected to develop over central South Dakota after 4 p.m. before tracking southeast through the evening. Storms may organize into a line, producing wind gusts up to 65 mph and quarter-size hail. While the overall severe weather threat is rated at Level 2 out of 5, scattered severe storms are possible across much of eastern South Dakota, including areas near Chamberlain, Mitchell, Huron, Brookings, Sioux Falls, Yankton, Madison, and Vermillion.
Heavy rainfall may become the most widespread hazard. Rainfall rates could exceed 2 inches per hour, with many communities receiving 0.50 to 1.5 inches. Where thunderstorms repeatedly track over the same area, localized totals of 4 to 5 inches are possible, significantly increasing the risk of flash flooding. Urban areas, low-lying roads, and flood-prone locations will be especially vulnerable to rapidly rising water.
Travel conditions could deteriorate quickly along Interstates 29 and 90, with reduced visibility, ponding on roadways, and isolated road closures during the heaviest downpours. Never drive through flooded roads, and ensure sump pumps are working properly before storms arrive.
Residents should have multiple ways to receive weather warnings and be ready to seek sturdy shelter immediately if severe thunderstorm warnings are issued. Additional watches or warnings may be issued through the evening as storms develop and move across the region.
