Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 407 AM EDT Sun Mar 22 2015 Valid 12Z Sun Mar 22 2015 - 12Z Tue Mar 24 2015 ...Heavy rain possible from the central Gulf Coast to the Southeast... ...Rain and snow will move into the Northwest U.S. by the end of the weekend... Gulf of Mexico moisture overrunning a surface frontal boundary stretched across the central Gulf Coast states will continue to produce moderate to heavy rains, with embedded thunderstorms, from the lower Mississippi Valley to the Southeastern states. The heavy rains will move eastward with time, ahead of a wave of low pressure along the front, and should come to an end by mid-day Monday as the low pushes off the northern Florida coast and high pressure filters in behind. Precipitation will be on the increase across the Northwest portion of the country through the end of the weekend as a system moves onshore by Sunday afternoon, traveling across the northern Rockies, and reaching the high Plains by Monday evening. This system will spread rain and higher elevation snows across the Northwest coast and Intermountain West on Sunday, moving into the northern Rockies and eventually the northern and central Plains by Monday. As usual, the most organized of the precipitation should remain confined to portions of the Pacific Northwest and northern California coasts, as well as favorable slopes of the northern Rockies. Elsewhere, light accumulating snow is possible from the northern Plains to the Midwest as weak energy moves through in the flow aloft. A wave of low pressure developing along the surface boundary may also bring a brief period of organized snow resulting in a narrow band of 4 to 6 inches across southeast Minnesota to the north of the low Sunday evening into early Monday morning. Meanwhile, a rapidly deepening system moving quickly through the Canadian Maritimes may clip northern Maine with some light snow showers Sunday into Monday. Santorelli Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php