Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 315 AM EDT Wed Sep 21 2016 Valid 12Z Wed Sep 21 2016 - 12Z Fri Sep 23 2016 ...Severe thunderstorms and flash flooding possible across portions of the Midwest... ...Locally heavy rain possible across portions of the southern Mid-Atlantic coast... ...Rain expected to spread across much of the interior West with snow by Friday for the highest elevations... A stalled frontal boundary extending from the central/northern plains to the Upper Great Lakes will serve as a focus for numerous showers and thunderstorms today into Thursday. Some storms may produce heavy rainfall, with multiple rounds of heavy rain possible for some areas, which could lead to flash flooding. Additionally, the Storm Prediction Center is forecasting a slight risk of severe thunderstorms today and tonight across portions of the Midwest. Areas of showers and thunderstorms will be possible across the coastal Southeast and southern Mid-Atlantic as a stationary frontal boundary and the remnants of Tropical Storm Julia continue to linger just offshore. Locally heavy rain is possible today, especially across coastal portions of the southern Mid-Atlantic region. Showers and storms should become a bit more scattered in nature by Thursday and Friday as the area of low pressure slowly drifts away from the coastline. Precipitation will begin to increase in coverage today across the interior West as a large upper-level low begins to move inland from the West Coast. Additionally, a wave of low pressure is forecast to develop along a stationary front, further increasing the large-scale support for precipitation. By late today showers and thunderstorms should be fairly numerous from Nevada and Utah north to Montana. On Thursday, rain and thunderstorms will continue for the same areas, while snow levels will begin to lower as the upper low moves east. By Thursday night into Friday morning, snow is possible at the higher elevations of the Wasatch, Tetons, and Bitterroot Ranges. Temperatures will be 5 to 15 degrees above average through Friday from the central/southern plains to the Great Lakes and Northeast as high pressure at the upper levels remains overhead. Meanwhile, temperatures will be dropping in the West as the upper-level low moves inland. By Thursday and Friday high temperatures across the interior west are forecast to be 10 to 20 degrees below average. Ryan Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php