Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 AM EST Tue Nov 19 2013 Valid 12Z Tue Nov 19 2013 - 12Z Thu Nov 21 2013 ...Unsettled weather expected across the West.... ...An arctic front will begin its plunge through the North Central U.S.... ...High pressure will keep weather dry and quiet across the Eastern U.S.... A cold front moving inland over the Pacific Northwest will trigger widespread shower activity as it sinks through the Western U.S. Tuesday and Wednesday. Pacific moisture surging onshore ahead of the front will make for moderate to heavy rains along coastal areas from Oregon down into central California. Farther inland over the Intermountain West and Rockies...precipitation should be mostly focused along the favored slopes of the terrain...but temperatures will be low enough to support accumulating snows along the higher elevations of the Northern/Central Rockies and Sierra Nevada ranges. East of the divide...an arctic front will begin its plunge through the North Central U.S.. Strong winds and plummeting temperatures will make for blustery conditions behind the front...and upslope flow into the terrain should force light to moderate snow showers over the Northern Rockies/Northern High Plains...with snows eventually spreading into the Dakotas on Wednesday. As the boundary dips farther south and east on Wednesday...southerly flow ahead of the front will siphon increasing amounts of moisture out of the Gulf...fueling scattered shower activity from the Southern Plains to the Upper Great Lakes. High pressure building in over the Eastern U.S. will keep weather dry and quiet through the middle of the week. An exception to this will be farther south...where a lingering frontal boundary could trigger some showers and thunderstorms along the Gulf Coast and across Florida the next few days. Also...as the strong surface high sets up over the Great Lakes on Wednesday...easterly flow off the Atlantic could bring some light precipitation into the Carolina coast. Gerhardt Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php