Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 459 AM EDT Tue May 07 2013 Valid 12Z Tue May 07 2013 - 12Z Thu May 09 2013 ...Wet and soggy conditions will continue to accompany a cut-off low creeping up the Eastern Seaboard... ...Widespread shower activity is expected across the Southwestern states in response to another closed low... ...Severe storms possible over the Central and Southern Plains... Wet and soggy conditions will continue to accompany a cut-off low creeping up the Eastern Seaboard the next few days. A plume of Atlantic moisture getting wrapped inland ahead of an occluded cold front will fuel moderate to heavy rains while the boundary lifts northward through the Mid-Atlantic states on Tuesday and into the Northeast on Wednesday. The closed low aloft will weaken with the time and precipitation should decrease in intensity...but the slow progression of the system combined with upslope flow will make flash flooding a concern along the eastern slopes of the Central Appalachians. Unsettled weather is expected across the Western U.S. as second cut-off low slowly makes it way inland toward the Four Corners region. Widespread showers and thunderstorms are expected over California...the Great Basin...and Central Rockies on Tuesday and Wednesday. Limited moisture across the region will keep precipitation totals light...but accumulating snows will be possible over the higher peaks of the Sierra Nevada range and Colorado Rockies. An increase in convection is expected across the Southern and Central Plains the next few days as the closed low in the Western U.S. edges eastward and low level southerly flow draws Gulf moisture northward. Ample amounts of instability will make severe weather a possibility with any developing storms. Please refer to the Storm Prediction Center for the latest information on the threat for severe storms. To the north of the convection...a strong cold front dipping down from Canada will drop temperatures as it sinks through the Dakotas and Upper Mississippi valley on Wednesday. Gerhardt Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php