Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 427 AM EDT Sat Apr 27 2013 Valid 12Z Sat Apr 27 2013 - 12Z Mon Apr 29 2013 ***Heavy rain and thunderstorms for parts of the South*** ***Scattered mainly light precipitation from the Pacific Northwest to the upper Midwest*** Showers and thunderstorms firing across portions of the southern Plains, Tennessee valley and the Southeast will continue to spread north and east ahead of a weak area of low pressure drifting east along the Texas/Oklahoma border. By this afternoon precipitation is expected to begin spreading further north across portions of the Ohio valley, southern Appalachians and the southern mid Atlantic states as the low drifts into the lower Mississippi valley. Meanwhile, storms are expected to organize ahead of the low's trailing cold front as it drops into southeast and south-central Texas by this evening. Fueled by ample moisture streaming north out of the Gulf of Mexico, these storms may have the potential to produce locally heavy rains. As the low continues its track to the northeast on Sunday, the leading edge of precipitation is expected to spread into the upper Ohio valley, lower Great Lakes and northern mid Atlantic regions. Storms are forecast to continue firing ahead of the trailing cold front extending back the western Gulf coast. Elsewhere, scattered and mainly light precipitation is expected across portions of the Pacific Northwest and northern Rockies today as a series of weak frontal boundaries move across the region. This is expected to spread across the northern Plains into the upper Midwest on Sunday as an area of better organized and heavier precipitation nears the Washington coast late in the day. Pereira Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php