Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 339 PM EDT Sun May 01 2016 Valid 00Z Mon May 02 2016 - 00Z Wed May 04 2016 ...Heavy rain and flash flooding possible from parts of the Lower Mississippi Valley to the Central Appalachians... ...Severe thunderstorms possible across portions of the Ohio Valley... Broad southwesterly flow ahead of a cold front will transport a warm and humid air mass northward across the eastern U.S. Showers and thunderstorms are expected along and ahead of the front as it slowly traverses the region. Locally heavy rainfall could lead to flash flooding across the lower Mississippi Valley today and then the lower Mississippi Valley to central Appalachians tomorrow. Portions of the Ohio Valley could see the development of strong to severe thunderstorms this afternoon. In the west, an upper level low over the Southwest will bring showers to parts of the Southwest and southern High Plains. Snow is expected across the highest elevations with some light accumulations possible in southern Colorado. The upper low is replaced by a strong ridge building over the western U.S. by Monday. Much above normal temperature are expected across much of the Pacific Northwest to northern High Plains. Krekeler Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php