Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 359 AM EDT Mon Mar 19 2018 Valid 12Z Mon Mar 19 2018 - 12Z Wed Mar 21 2018 ...Severe thunderstorms expected from the eastern Tennessee Valley to parts of the Southeast... ...Heavy snow possible expected for parts of the Northern/Central Rockies... ...Heavy rain possible over parts of the Southeast... ...Snow for portions of the Northern Plains into parts of the Upper Mississippi Valley... A low pressure system will track from the Central Plains eastward to the Southern Appalachians/southern Mid-Atlantic by Tuesday before it pushes offshore the Carolina coast, deepens and tracks northeast. Snow over the Central Plains will slowly move into parts of the Middle Mississippi Valley by Tuesday. Along and ahead of the front, where warm moist air transports northward from the Gulf, will generate showers and thunderstorms across the eastern Gulf states, eastern Tennessee Valley and parts of the Southeast. The Storm Prediction Center has highlighted these are areas as having a slight risk for severe weather, with an enhanced risk over central Tennessee and northeast Mississippi, northern Alabama and northwest Georgia. Heavy rain will also be possible from these storms; therefore a marginal risk for excessive rainfall has been issued by the Weather Prediction Center. Light snow will also develop over parts of the Central Appalachians on Tuesday. Meanwhile, upper-level energy over parts of the Northern High Plains will move eastward into parts of the Upper Mississippi Valley by Tuesday; which will help generate snow over parts of the Northern Intermountain Region/Northern Rockies into parts of the Northern Plains and will expand into the Upper Mississippi Valley into Tuesday morning. A second area of upper-level energy just off the Pacific Northwest Coast will slowly begin to move inland overnight Monday into Tuesday morning. Onshore flow will this system will result in coastal rain and higher elevations snow over the Pacific Northwest through Tuesday. By Tuesday night rain will begin over portions of California. This upcoming event could lead to increased flooding concerns. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php