Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 PM EDT Sun May 17 2020 Valid 00Z Mon May 18 2020 - 00Z Wed May 20 2020 ...Tropical Storm Arthur is forecast to move close to the North Carolina coast overnight into Monday... ...Heavy rainfall and flash flooding expected with thunderstorms over portions of the Midwest through tonight and the Ohio Valley Monday... ...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 expected to move northward overnight and approach the Outer Banks of North Carolina. 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. A surface low pressure system is forecast to slowly meander over the Ohio Valley over the next couple of days, and rain and thunderstorms are likely in its vicinity and southward along its associated warm front. Today into tonight, a Moderate Risk of flash flooding and a Slight Risk of severe weather are in place for much of Illinois and western parts of Indiana, with some severe and flash flooding risk stretching farther south as well. Then on Monday, a Moderate Risk of flash flooding is outlined across portions of the Ohio Valley, with a Slight Risk of excessive rainfall farther north over the Upper Great Lakes and southward toward the Southern Appalachians. Flash Flood and Flood Watches are also in effect, and strong to severe thunderstorms are also possible. A frontal system will continue to move slowly eastward across the Intermountain West over the next couple of days ahead of a deep upper-level low making its way into the West Coast. 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 today through Tuesday for portions of the Southwest, Central Great Basin, and Four Corners. Red Flag Warnings are also in effect. Tate Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php