Thunderstorms hurled high winds, heavy rain, hail and intense lightning across the northern Plains and South. A cold front moving across the northern tier states produced scattered thunderstorms from the Dakotas to Minnesota and northern Iowa. Winds gusted to 61 m.p.h. at Eden, S.D., and pea-size hail pelted Webster, S.D. In Sioux Falls, S.D., the storm was blamed for knocking out power to about 8,500 customers of Northern States Power Co. for about three hours.