Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 442 PM EDT Thu Mar 19 2015 Valid 00Z Fri Mar 20 2015 - 00Z Sun Mar 22 2015 ...Developing coastal low will bring Spring snow to the northern Mid-Atlantic states on Friday... ...Heavy rains and flash flooding expected over eastern Texas late this week... Widespread wet and stormy weather will continue to fire up along a wavy frontal boundary stretched from the Southwest to the southeastern U.S.. Energy aloft will help strengthen a surface wave along the front...which is expected to deepen while tracking up the Eastern Seaboard Thursday night into Friday. A batch of moderate to heavy precipitation should lift through the Mid-Atlantic states with the low...and enough cold air on the back edge of the developing coastal storm could cause accumulating Spring snows along the Appalachians and eastward across Pennsylvania and southern New England. Farther west along the wavy frontal boundary stretched through the southern tier of the Nation...an organized area of showers and thunderstorms should focus along a portion of the front gradually sinking through the southern Plains Friday and Saturday. Increasing amounts of Gulf moisture feeding into the slow moving storms could lead to heavy rains and flash flooding across eastern Texas and portions of the Lower Mississippi Valley. Elsewhere across the Country...light snows and a shot of cooler air will accompany a cold front plunging through the northern Plains and Upper Great Lakes late this week...and a Pacific front slowly approaching the West coast should keep light to moderate rain in the forecast for much of the Pacific Northwest. Gerhardt Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php