Baseball-sized hail and tornadoes are possible across parts of North and South Dakota, which are in the bull's-eye of a sprawling severe weather threat that stretches from the Dakotas to the Texas Panhandle and eastern New Mexico. Severe thunderstorms are expected to redevelop by mid-afternoon Tuesday across the entire Great Plains. There's a mounting flood threat particularly in North Dakota and across eastern New Mexico and West Texas, where repeated rounds of storms could bring heavy rainfall and flash flooding.