Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 406 PM EDT Mon Mar 13 2017 Valid 00Z Tue Mar 14 2017 - 00Z Thu Mar 16 2017 ...Late-season winter storm for the East Coast on Tuesday... ...Arctic air will remain in place across much of the central and eastern U.S. through much of the week... It continues feeling like winter across much of the country, despite it being mid-March. A large surface high pressure ridge over south-central Canada is sprawling southward into the central and eastern U.S., allowing for a continuous supply of arctic air and January-like temperatures through the middle of the work week. Afternoon highs are expected to be on the order of 15 to 30 degrees below normal from the northern Plains to the Mid-Atlantic region, with the possibility of some record low maximum temperatures in the Mid Atlantic by midweek. Freeze warnings are currently in place for much of the Mid Mississippi Valley and portions of the western Ohio Valley through Thursday. Things get interesting for the East Coast beginning this evening and tonight. A low pressure system currently moving northeast across the Ohio Valley is expected to phase with another low off the southeast U.S. coast by Tuesday. This will allow for a strong nor'easter to develop near the coast, producing a late-season snowstorm from the central Appalachians to New England, including many of the large cities in the Northeast U.S. Widespread winter storm warnings are in effect for heavy snowfall accumulations from the northern Mid Atlantic through the entire Northeast U.S., with some areas likely getting in excess of a foot from eastern Pennsylvania to southern New England. The tricky part of the forecast deals with the rain/snow/ice line over the Mid-Atlantic region with a tight gradient in accumulations expected near the greater Washington DC metro area. Closer to the coast from southern New Jersey to the Carolinas, rain is expected with amounts in excess of an inch likely. Elsewhere across the continental U.S., onshore flow will once again be the story across the Pacific Northwest. This will keep rain showers in play across much of the Pacific Northwest and Northern Great Basin over the next few days. The impending rainfall will combine with above freezing temperatures and snow melt, leading to flooding concerns from the Pacific coast inland into the Northern Rockies. Flood watches, advisories, and hydrologic outlooks are in place as a result. Warm conditions will continue across the southwestern U.S. with no rain or snow in the forecast. The lower elevations of the Desert Southwest could even reach the lower 90s for highs over the next few days with an upper level ridge in place. D. Hamrick/Wix Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php