Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 235 PM EST Mon Feb 18 2019 Valid 00Z Tue Feb 19 2019 - 00Z Thu Feb 21 2019 ...Heavy rain possible from the Central Appalachians into the Ohio, Tennessee, and Lower Mississippi Valleys... ...Heavy snow possible over parts of the Cascades, Central/Southern Rockies, Central Plains into Upper Great Lakes, and over parts of the Mid-Atlantic/Central Appalachians... ...Rain/Freezing rain possible over parts of the Central/Southern Appalachians... ...Temperatures will be 15 to 26 degrees below average over the Plains/Rockies and Great Basin... A storm over the Central/Southern Rockies will move southeastward to the Western Gulf Coast by Tuesday and move northward to the Middle Mississippi Valley by Wednesday. The system will produce snow over parts of the Northern Intermountain Region, Great Basin, and the northern parts of the Southwest along with the Central/Southern Rockies on Monday evening. The snow will move eastward into parts of the Southern/Central Plains and Middle Mississippi Valley by Tuesday evening. The snow will continue to move into parts of the Northern Plains/Upper Mississippi Valley by Wednesday morning. The snow will also move into parts of the Ohio Valley, Central Appalachians, and Northern Mid-Atlantic by Wednesday morning, too. By Wednesday evening snow will move into the Upper Great Lakes. Additionally as the system moves out of the Rockies, moisture from the Western Gulf of Mexico will move northward over over parts of the Southern Plains eastward to the Southeast. The moisture will advances as far north as the Middle Mississippi Valley/Ohio Valley overnight Tuesday and into Ohio Valley/Mid-Atlantic by Wednesday evening. The storm will also produce rain over the lower elevations of the Southwest on Monday evening that will change over to snow by Tuesday morning. In addition as the moisture from the Gulf of Mexico moves inland over the Western/Central Gulf Coast, showers and thunderstorms will develop along and in just inland over parts of the Western/Central Gulf Coast on Tuesday. Rain will develop farther inland over parts of the Southern Plains, Lower Mississippi and Tennessee Valleys as well as parts of the Southeast also on Tuesday. The rain will become heavy at times. The heavy rain and thunderstorms will move northward overnight Tuesday into the Ohio Valley continuing into Wednesday. On Wednesday morning, rain/freezing rain will develop over parts of the Southern Appalachians that will move northward into the Central Appalachians by Wednesday evening. There is a slight to Moderate risk of excessive rainfall from the Lower Mississippi/Tennessee Valleys into parts of the Ohio Valley from Tuesday into Wednesday. Meanwhile, upper-level energy over parts of the North Pacific into Western Canada will move southward along the West Coast to Northwestern Mexico by Wednesday that will be followed by a much stronger area of upper-level energy on Wednesday. The energy and developing onshore flow will aid in producing rain and higher elevation snow over parts of the Pacific Northwest on Tuesday evening. Overnight Tuesday, the snow will expand inland into parts of the Northern Rockies and Great Basin. As the energy moves farther south over the West Coast, rain and higher elevation snow will develop over parts of California and moves farther inland over the Great Basin by Wednesday evening. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php