Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 315 AM EST Sun Dec 04 2016 Valid 12Z Sun Dec 04 2016 - 12Z Tue Dec 06 2016 ...Heavy rain possible from the Western Gulf Coast to portions of the Southeast and Southern Appalachians... ...Heavy snow possible over parts of the Cascades... A front over the Northwest will move eastward to the Upper Mississippi Valley/Central Plains and southward to the Great Basin and Central Rockies by Monday evening. The system will produce rain and higher elevation snow over the Pacific Northwest and snow over the Northern Intermountain Region/Northern Rockies with the snow moving to the Northern Plains/Central Rockies by Monday afternoon and into parts of the Upper Mississippi Valley/Upper Great Lakes by Monday evening. Onshore flow will aid in keeping rain and higher elevation snow over the Pacific Northwest through Tuesday. Meanwhile, upper-level energy over the Northern/Central Plains will move eastward to the Great Lakes overnight Sunday and into parts of Southeastern Canada and the Northeast by Monday evening. The energy will aid in producing snow over parts of the Upper/Middle Mississippi Valley and Upper Great Lakes that will move eastward to Northern New England by Monday evening. Rain will also develop over parts of the Central Plains/Middle Mississippi Valley and the southwestern portion of the Ohio Valley that will move into parts of the Mid-Atlantic by Monday morning and off the Mid-Atlantic Coast by Monday evening while lingering over parts of Southern New England. In addition, an upper-level low over Northwestern Mexico will slowly move eastward to Eastern Texas by Monday evening. Circulation around the upper low will stream moisture into the Western Gulf Coast and eastward into the Eastern Gulf Coast/Southeast on Sunday. The moisture will continue to flow northward out of the Gulf of Mexico overrunning the associated front through Monday night. Showers and thunderstorms will develop over parts of the Western Gulf Coast into parts of the Eastern/Central Gulf Coast on Sunday expanding into parts of Southeast by Monday morning continuing into Monday evening. Rainfall with some of these thunderstorms will be heavy at times. Rain will develop over parts of the Southern Plains eastward to Southern Ohio Valley/Southern Appalachians moving into the Southern Mid-Atlantic and the Carolinas overnight Sunday. The rain will end overnight Sunday over parts of the Middle Mississippi Valley/Tennessee Valley and ending over the Southern Mid-Atlantic/Carolinas by Monday evening. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php