Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 253 AM EDT Thu Mar 21 2019 Valid 12Z Thu Mar 21 2019 - 12Z Sat Mar 23 2019 ...A developing coastal storm to bring rain, interior and higher elevation snows, and gusty winds to parts of the Mid-Atlantic and Northeast... ...A couple rounds of rain and mountain snows likely across parts of the West during the short range, with rain moving into the Southern and Central Plains by Friday... ...Major to historic river flooding will continue across parts of the Mississippi and Missouri River Basins with areal flooding a threat across parts of the Northwest and Northern Plains as well... The main sensible weather threat in the short range with be a developing coastal low pressure system off the Carolina coasts this morning, tracking up the east coast through Thursday and into Friday. Moderate to locally heavy rainfall will accompany this system across the Mid-Atlantic and Northeast with flash flooding a marginal and local threat particularly for highly urbanized areas. A handful of flood watches are in effect across parts of the Mid-Atlantic. Accumulating snowfall is also possible well inland across portions of the interior Northeast. Gusty winds are also likely across the Mid-Atlantic and Northeast into the weekend as the storm deepens as it moves up the coast. Meanwhile, a cold front moving into the Four Corners region this morning will continue to produce rain and mountain snows across parts of the Southwest and into the Southern Rockies on Thursday. As moisture get drawn northward from the Pacific ahead of the cold front, precipitation is expected to spread into parts of the southern and central Plains on Friday as well. Another cold front entering the West Coast states by late Friday will bring more rain and higher elevation snows to California, the Pacific Northwest, and parts of the interior West this weekend. Major to historic and catastrophic flooding across parts of the Missouri and Mississippi River Basins will continue through the short range due to ongoing effects following a period of rapid snow melt after heavy rainfall last week. Flood warnings and advisories remain for parts of the region. Areal flooding is also a concern across parts of the Northwest and into the Northern Plains as warmer temperatures the end of this week lead to accelerated snowmelt and the potential for ice jams. Santorelli Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php