Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 417 PM EDT Sat Jul 20 2013 Valid 00Z Sun Jul 21 2013 - 00Z Tue Jul 23 2013 ...Showers and thunderstorms continue from the Mid-Atlantic/Southeast to the Plains states... ...Showers and thunderstorms possible from the Gulf Coast to the Southwest U.S.... A cold front extending from the Mid-Atlantic through the Ohio Valley and into the Central Plains will drift slowly southward before stalling across the Mid-Atlantic states on Sunday morning. The chance for showers and thunderstorms will remain in the forecast along and ahead of the boundary from the Mid-Atlantic to the Middle Mississippi Valley and Central Plains through at least Monday. Weak impulses of upper level energy could also enhance precipitation just along the front in the Ohio Valley as well as in the Central Plains. Farther north, another area of upper level energy over southwest Canada will dive southeastward into and across south central Canada. At the surface, a system over the Canadian Rockies will strengthen and accelerate as it drops into the Northern Plains on Sunday and lifts into the Upper Midwest/Northern Great Lakes on Monday. Showers and thunderstorms will develop ahead of the warm front on Sunday across the Northern Plains and into the Upper Great Lakes by Monday. Elsewhere, more upper level energy will induce showers and storms at the surface across the central Gulf Coast states and into the Southeast. Across the southwest, monsoonal moisture and the weak upper low over Mexico will keep the scattered showers and thunderstorms across the region on Sunday but should begin to dissipate by Monday morning. Monarski Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php