Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 416 AM EDT Mon May 18 2020 Valid 12Z Mon May 18 2020 - 12Z Wed May 20 2020 ...There is a moderate risk of excessive rainfall over the Ohio Valley... ...Rain and higher elevation snow forecast to continue across portions of the West... ...Fire weather danger will be widespread across portions of the Central Great Basin, Southwest, and Four Corners region... ...Tropical Storm Arthur is forecast to move close to the North Carolina coast Monday morning... A storm over the the Ohio Valley/Great Lakes will produce very heavy rain over parts of the Ohio Valley/Great Lakes into the Southern Appalachians. The WPC has issued a moderate risk of excessive rainfall over the Ohio Valley The Heavy rain will aid producing numerous areas of flash flooding which may also impact larger rivers. Also, the WPC has issued a slight risk of excessive rainfall over the Southern Appalachians northward into the Great Lakes. Here the heavy rain will aid in producing mainly localized areas of scattered flash flooding. The region of heavy rain will move into the Central/Southern Appalachians on Tuesday into Wednesday. A system over the Western U. S. will continue to move slowly eastward across the Intermountain West. Pacific moisture should continue to cause precipitation in the Pacific Northwest, California, and increase over the Great Basin Monday and Tuesday. While most precipitation will fall as rain, the Sierra Nevada could receive several inches of snow, and some Winter Storm Warnings are in effect. In between the upper-level low in the West and the systems in the eastern half of the country, upper-level ridging is expected across the Great Basin into the Rockies and Plains. This will lead to temperatures that are above average by 10 to 20 degrees in those areas underneath the ridge. The dry, hot conditions could also cause fire danger, and the Storm Prediction Center has Elevated to Critical Risks for fire weather in place through Tuesday for portions of the Southwest, Central Great Basin, and Four Corners. Red Flag Warnings are also in effect. Tropical Storm Arthur is expected to move northeastward out over the Western Atlantic this afternoon after its close approach to North Carolina. Currently Tropical Storm Warnings are in effect for portions of the North Carolina coast, where tropical-storm-force winds are expected along with locally heavy rain. Dangerous coastal surf and rip currents are forecast to spread northward from the Southeast into the Mid-Atlantic over the next couple of days. Please see the National Hurricane Center for more information on Arthur. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php