Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 345 PM EST Fri Dec 20 2013 Valid 00Z Sat Dec 21 2013 - 00Z Mon Dec 23 2013 ...There is a slight risk of severe thunderstorm over parts of the Western Gulf Coast/Lower Mississippi Valley... ...Heavy rain possible from the Lower Mississippi Valley to parts of Northern New England... ...A band of snow is expected from the Central Plains to the Great Lakes and across parts of Northern Maine... ...Freezing rain possible from parts of the Southern Plains to the Great Lakes to parts of New England... A quasi-stationary front extending from the Southern High Plains to the Northeast will have a strong wave of low pressure move along the boundary from roughly New Mexico to the Great Lakes/Ohio Valley. The front associated with the strong wave will move from Northern Mexico eastward to the Ohio/Tennessee Valleys to the Central Gulf Coast by Sunday. Moisture from the Gulf of Mexico will pool along the quasi-stationary front producing regions of showers and thunderstorms from the Southern Plains to the Tennessee Valley, with the associated rain, heavy at times. In addition, a band of light to moderate rain will develop from Southern Plains to parts of New England, becoming moderate to heavy at times. Next, a band of freezing rain/sleet will develop from parts of Oklahoma across parts of the Great Lakes into parts of New England, some of these regions will be intermittent and changing. A weaker wave over the Ohio Valley/Great Lakes will move eastward to New England by Saturday evening. Snow will develop over parts of the Upper Great Lakes into Northern Maine, Friday evening into Saturday, with snow ending over parts of the Upper Great Lakes by Saturday morning. Additionally as the strong wave moves out of Mexico, showers and thunderstorms will develop over Texas overnight Friday moving eastward to the Central Appalachians/Tennessee Valley/Western Gulf Coast by Sunday morning. The system will produce snow over parts of the Central/Southern Rockies Friday evening into Saturday morning. Another region of snow will develop over parts of the Southern Plains on Saturday afternoon that will move into the Middle Mississippi Valley/Upper Great Lakes by Sunday morning, while the snow intensifies over Northern Maine by Sunday morning, too. Meanwhile, upper-level energy will move into the Pacific Northwest and move southeastward to the Southern Rockies by Sunday. A plume of Pacific moisture will come onshore with the energy producing coastal rain and higher elevation snow over the Pacific Northwest through Sunday. The energy will also develop snow over parts of the Northern Rockies that will expand into parts of the Central Rockies and Northern High Plains, also through Sunday morning. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php