Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 357 AM EDT Tue May 19 2020 Valid 12Z Tue May 19 2020 - 12Z Thu May 21 2020 ...There is a moderate risk of excessive rainfall over parts of the Southern Appalachians ... ...There is a slight risk of severe thunderstorms over parts of the Northern High Plains... ...Tropical Storm Arthur to produce dangerous surf conditions and rip currents along the Mid-Atlantic Coast... ...Critical fire weather conditions to continue across portions of the Southwest and Four Corners Region... A slow-moving storm will continue to produce heavy rains across portions of the Southern Appalachians and the Southern Mid-Atlantic on Tuesday and Wednesday. This system is expected to produce several inches of rain, with flash flooding likely, especially across portions of Southern Appalachians and Mid-Atlantic Tuesday and Wednesday. Meanwhile, an upper level low moving east from the Eastern Pacific is expected to produce widespread precipitation across the Western U.S. This includes higher elevation snow, with several inches forecast to accumulate across the higher peaks of the Sierra Nevada Mountains. Significant rains along with snowmelt will also raise flooding concerns across portions of the Northwest and Northern Rockies. In addition, the SPC has issued a slight risk of severe thunderstorms over parts of the Northern High Plains with the main threats of damaging thunderstorm wind, hail, and tornadoes. Dry and windy conditions will prevail across the Southwest -- promoting elevated to critical fire weather conditions across much of the Southwest through the Four Corners region on Tuesday. Farther east, Tropical Storm Arthur will continue to track east away from the North Carolina Outer Banks. However, dangerous coastal surf conditions and rip currents are forecast to spread north along the Mid-Atlantic Coast and persist during the next couple of days. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php