Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 416 PM EST Sun Feb 19 2017 Valid 00Z Mon Feb 20 2017 - 00Z Wed Feb 22 2017 ...There is a slight risk of severe thunderstorms over parts of the Southern Plains... ...Heavy snow possible for the Sierras, Sawtooth, and Wind River Mtns/Absaroka Range... ...Heavy rain possible for portions of Northern/Central California and Pacific Northwest... ...Heavy rain possible for portions Western/Central Gulf Coast... A deep upper-level trough over the Central/Southern Rockies will form a new closed upper-level low over the Western Gulf Coast by Tuesday. The storm will produce snow and lower elevation rain over parts of the Central/Southern Rockies and the Southwest that will come to an end by Monday morning. In addition, moisture from the Gulf of Mexico will stream northward over the Southern/Central Plains and extending into the Great Lakes by Monday evening. Showers and thunderstorms will develop over parts of the Southern Plains by Sunday evening that will expand into parts of the Central Plains/Middle Mississippi Valley by Monday morning. By Monday evening, the showers and thunderstorms will withdraw to Lower Mississippi Valley and into the Central Gulf Coast by Tuesday. Overnight Monday, rain will develop over parts of the Tennessee Valley. Additionally, northern stream upper-level energy associated with the deep upper-level trough over the Rockies will move to the Great Lakes by Tuesday morning. The energy will aid in producing rain over parts of the Northern Plains/Upper Mississippi Valley overnight Sunday into Monday morning that will move into the Great Lakes/Western Ohio Valley by Tuesday morning. Meanwhile, another upper-level trough will begin to move onshore over the West Coast on Monday afternoon into Tuesday. Ahead of the trough, a plume of moisture from the Pacific will move into Central/Southern California that will move southward to Southern California when the plume of moisture will start to wane by Tuesday. The influx of moisture will aid in producing rain along the West Coast with snow at higher elevations over California and the Pacific Northwest through Tuesday. Snow and lower elevation rain will also develop over parts of the Northern Intermountain Region and Northern Rockies through Tuesday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php