Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 405 PM EDT Thu Jun 06 2019 Valid 00Z Fri Jun 07 2019 - 00Z Sun Jun 09 2019 ...Multi-day heavy rain event with possible flash flooding from the lower Mississippi Valley and Gulf Coast into the southern Appalachians and southern Mid-Atlantic through the weekend... ...Severe weather threats for portions of south-central Texas and the northern Great Basin, northern Rockies this evening, refocusing into the northern High Plains for Friday... ...Strong cold front to move through the northwestern U.S. through Saturday... Deep, tropical moisture ahead of an upper level system, currently over the southern Plains, will continue to support widespread moderate to heavy rains as it moves east into the lower Mississippi valley through Friday. The heaviest rainfall through Friday morning is expected from Oklahoma into Arkansas where 2-4 inches will be possible while the focus for heavier rain translates east for Friday into portions of the Tennessee Valley and southern Appalachians. The central and eastern Gulf Coast is expected to see multiple days with a heavy rain threat with the potential for 4-8 inches from southern Alabama into the Florida Panhandle. Scattered thunderstorms with flash flood potential will also exist south of an east-west oriented cold front moving south through the Mid-Atlantic region and Ohio Valley. In addition to heavy rain, strong to severe thunderstorms are also a concern, especially for portions of south-central Texas to the coastal plain this evening where the Storm Prediction Center is indicating an Enhanced Risk for severe thunderstorms producing damaging winds and large hail Thursday afternoon and evening. From Friday through Saturday, as the upper system continues to drift east, the heavy rain and flash flooding threat is expected to extend farther east into the southern Appalachians and southern Mid-Atlantic. Across the West, a strong cold front is forecast to push east into the northern Rockies and Great Basin tonight into the weekend. Strong to severe storms are expected to develop ahead of the front, with a Slight Risk for severe weather indicated by the Storm Prediction Center this evening into the overnight from central Montana into the northern Great Basin. On Friday, as the front continues to move farther east, the severe weather threat is expected to shift out into portions of eastern Montana and Wyoming and the western Dakotas. Significantly colder temperatures will follow the front, with daytime highs 10-20 degrees below average expected from the Pacific Northwest into central Montana and the northern Great Basin on Friday, before spreading farther east across the northern High Plains for Saturday. By early Friday morning and continuing into the weekend, a wintry mix can be expected across the higher elevations of the Pacific Northwest mountain ranges, as well as the northern Rockies with minor accumulations across the higher elevations of Idaho into western Montana and northwestern Wyoming through Sunday morning. Otto Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php