Thunderstorms are expected to move into south-central South Dakota by 10 PM this evening. Between 10 PM and 12 AM these storms will move into southeast South Dakota and northeast Nebraska. Through 4 AM, they will spread northeast into southwest Minnesota and northwest Iowa. Initially, the storms will be capable of producing hail up to walnut size and wind gusts up to 70 mph. Later, the storms will gradually decrease in intensity, producing hail up to quarter size and wind gusts up to 60 mph. A moderate threat of these conditions exists generally south of Interstate 90 and west of Interstate 29, with a low threat further north and further east. The majority of the storms should remain west of U. S. Highway 71 in southwest Minnesota and northwest Iowa overnight.