More than 33 million Americans are in the bull's-eye of a flash flood threat across North and East Texas, as well as Oklahoma, Arkansas, Kansas and Missouri. Days of storms are expected to soak this region and other parts of the Deep South and Southeast Coast through the Memorial Day weekend, as a plume of tropical moisture from the Gulf hangs over this part of the country. This is part of a stagnant weather pattern where this moisture will interact with and enhance a series of slow-moving storms through the weekend which will form along a stalled front. A localized downpour triggered heavy flash flooding over downtown Atlanta during the height of the afternoon rush Wednesday.