Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 310 PM EST Tue Jan 20 2015 Valid 00Z Wed Jan 21 2015 - 00Z Fri Jan 23 2015 ...Heavy rain possible over parts of the Southern Plains... ...Heavy snow possible over parts of the Southern Rockies... ...Temperatures will be 10 to 15 degrees below average over the Southern/Central High Plains... Upper-level energy over the Northern Plains will move eastward off the Mid-Atlantic Coast by Thursday. The energy will produce light snow over part of the Northern Plains/Upper Mississippi Valley that will expand into the Ohio Valley by Wednesday morning. The light snow will move into the Ohio Valley/Northern Mid-Atlantic Wednesday afternoon into evening, ending overnight Wednesday. Light rain will also develop over parts of the Southern Ohio Valley/Mid-Atlantic Wednesday afternoon into evening, too. Additionally, upper-level energy moving across the Gulf Coast will produce light rain over parts of the Eastern Gulf Coast Tuesday evening into Wednesday morning. Meanwhile, upper-level energy over Southern California and the Northern High Plains will merge to form a upper-level low over the Southern Rockies/Southwest by Thursday morning. The system will produce snow over parts of the Southwest to Central/Southern Rockies on Wednesday morning that will move into parts of the Southern High Plains Wednesday evening into Thursday morning. As the energy moves over the Southern Rockies, moisture from the Western Gulf of Mexico will stream into the Southern Plains producing rain over the region Wednesday evening into Thursday. Elsewhere, upper-level energy will begin to move into the Pacific Northwest Wednesday evening that will aid in producing light rain and higher elevation snow over parts of the Northwest, likewise, Wednesday evening into Thursday morning. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php