Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 321 AM EST Thu Jan 21 2016 Valid 12Z Thu Jan 21 2016 - 12Z Sat Jan 23 2016 ...Significant winter storm to affect a region stretching from the Ozarks to the Mid-Atlantic through early Saturday... ...Severe weather is possible across the central/eastern Gulf coasts... ...Heavy rainfall will spread along the West Coast... Water vapor imagery early this morning showed an upper trough moving through the Central Plains. This system is expected to strengthen rather markedly as it dips down into the southern U.S. and eventually lifts northward reaching the Carolinas by Saturday morning. The initial surface low which tracks across the Tennessee valley will give way to deepening coastal low. This latter feature takes over and becomes a dominant force in setting up heavy snow bands over the Mid-Atlantic and very gusty winds. With all that said, the National Weather Service hazards page displays a winter storm watch stretching from the Tennessee valley into the interior Carolinas and up into the Central Appalachians/Mid-Atlantic region. Even a blizzard watch is in effect across the Washington, D.C. metro area along with adjacent locations. The current forecast indicates high snowfall totals are possible from Kentucky eastward into the Southern/Central Appalachians and across the Mid-Atlantic. Many of these locations will be measuring the snow in feet, particularly from Washington, D.C. and Baltimore back into the higher terrain of West Virginia and Virginia. While there is a lot of focus on the heavy snow and blizzard conditions, significant icing is likely to the south. The current forecast calls for at least 0.10 inches of ice accumulations from southeastern Missouri across southern Kentucky and over much of the western/central Carolinas. For the latest information on this developing winter storm, please view the heavy snow/ice discussion (QPFHSD) issued by the WPC winter weather desk. Given the robust nature of the closed low tracking along southern tier of the nation, an active period of thunderstorms is expected over much of the central/eastern Gulf coasts. Many of these storms may become severe per the latest convective outlook from the Storm Prediction Center. The forecast on Thursday suggests an enhanced risk of severe storms with tornadoes being a likely threat from far southeastern Texas across southern Louisiana/Mississippi, and into the far western Florida Panhandle. This convective threat will slide eastward by the following day as the upper low accelerates to the east. A broad, deep upper trough positioned over the western U.S. will foster the development of abundant rainfall along the immediate coast. Regions of enhanced orographic lift can expect the highest totals which includes the Shasta, Sierra Nevada, Olympics, and Washington Cascades. Given the strong Pacific influence of this air mass, snow should generally concentrate over the highest elevations of the West. Rubin-Oster Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php