There is a Slight Risk of excessive rainfall over parts of the SouthernPlains/Lower Mississippi Valley...Light snow over parts of the Cascades on Saturday night into Sunday.Strong to severe thunderstorms from the southern Mid-Atlantic,Southeast to the Southern PlainsA front extending from the Southeast westward to the Western Gulf Coastwill slowly move southward of the Florida Peninsula by Monday evening.Showers with strong to severe thunderstorms will develop along theboundary. Therefore, the SPC has issued a Marginal Risk (level 1/5) ofsevere thunderstorms over parts of the Mid-Atlantic to the Central GulfCoast through Sunday morning. The hazards associated with thesethunderstorms are frequent lightning, severe thunderstorm wind gusts,hail, and a minimal threat of tornadoes.Additionally, a second area of showers with strong to severe thunderstormswill develop over parts of the Southern Plains. Therefore, the SPC hasissued a Marginal Risk (level 1/5) of severe thunderstorms over parts ofthe Southern Plains through Sunday morning. The hazards associated withthese thunderstorms are frequent lightning, severe thunderstorm windgusts, hail, and a few tornadoes.The showers and thunderstorms will also produce heavy rain over parts ofthe Southern Plains/Lower Mississippi Valley. Therefore, the WPC hasissued a Slight Risk (level 2/4) of excessive rainfall with thesethunderstorms through Sunday morning. The associated heavy rain willcreate mainly localized areas of flash flooding, with urban areas, roads,small streams, and low-lying areas the most vulnerable.On Sunday, the strong to severe thunderstorm threat and the excessiverainfall threat have come to an end. However, showers and thunderstormswill continue over parts of the Southeast to the Central Gulf Coast.Meanwhile, a front over the Pacific Northwest/Northern IntermountainRegion will move eastward to the Upper Mississippi Valley to the CentralPlains and then to the Great Basin by Monday evening. The system willproduce rain over parts of the Pacific Northwest Coast through Sundayevening. Furthermore, overnight Saturday, light snow will develop over theCascades and parts of the Northern Intermountain Region by early Sundaymorning, ending overnight Sunday.On Monday, as the boundary moves onto the Plains, a weak plum of moistureflows from the Western Gulf of Mexico to the Upper Midwest, aiding in thedevelopment of rain over parts of the Northern Plains and the UpperMississippi Valley. Elsewhere, a front moving across Florida will produceshowers with strong to severe thunderstorms.