Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 251 AM EST Thu Feb 20 2020 Valid 12Z Thu Feb 20 2020 - 12Z Sat Feb 22 2020 ...Snow for the Carolinas and lake effect snow down wind from the Great Lakes... ...Additional rain likely across flooded regions of the South through Thursday.... ...Temperatures will be 10 to 25 degrees below average over the Upper/Middle Mississippi Valley, Southern Plains, and parts of the Northern/Central Rockies into the Southeast... Up to 1.5 inches of additional rain will fall over parts of the Lower Mississippi Valley to the Southeast mainly on Thursday. Overrunning moisture and upper-level energy will aid in producing rain over areas hit by Heavy rain during the last 14 days. The WPC has issued a marginal risk of excessive rainfall over this area. Flash flood watches are up over this area. The marginal risk means isolated flash flooding is possible. Meanwhile, a cold dome of Arctic high pressure pushing down across the Rockies and Plains will spread east-southeastward over the Lower Mississippi Valley to the Ohio Valley and the Southeast. This high will keep temperatures 10 to 25 degrees below average for this part of the country. The cold air will support accumulating snow on Thursday evening into Friday evening over the Southern Appalachians, eastward across much of North Carolina, Northern South Carolina and Southern Virginia where locally several inches of snow are expected. In addition, with the cold air flowing over the Great Lakes, lake effect snow will develop on Friday. The heaviest snow will be down wind from Lakes Ontario and Erie. Elsewhere, dry weather will persist across much of Western U.S. from the West Coast into the Great Basin and the Northern Rockies. However, there will be a weak area of low pressure coming into the Southwest by Saturday which will bring some clouds and showers along with temperatures trending below normal. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php