Sioux Falls, South Dakota – Strong to severe thunderstorms are expected to develop across eastern South Dakota this afternoon and evening, with the highest threat centered along and east of Highway 81. Large hail up to the size of ping pong balls and wind gusts near 60 mph could impact travel and outdoor activities into Sunday night.
According to the National Weather Service in Sioux Falls, storm coverage and location remain uncertain, but counties near Highway 81—including Yankton, Mitchell, and Brookings—face the greatest risk for damaging conditions. Rainfall rates could be heavy enough to cause localized flooding in low-lying areas and poor-drainage spots, especially during evening hours.
Communities including Sioux Falls, Watertown, and Vermillion may experience brief but intense downpours, hail accumulation, and isolated wind damage. Drivers are urged to monitor changing conditions and avoid flooded roads. Residents should secure loose outdoor items and remain weather-aware through the evening.
Additional storms are expected Monday, particularly in southwest Minnesota, with an Enhanced Risk for severe weather. Hail up to golf ball size or larger and wind gusts to 65 mph are possible. The setup may also support isolated tornadoes, though uncertainty remains in exact storm placement.
Storm warnings remain in effect into Monday night. More updates will be issued as new data becomes available.
