Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 409 AM EDT Sun May 19 2013 Valid 12Z Sun May 19 2013 - 12Z Tue May 21 2013 ...Moderate risk of severe weather for eastern Kansas and northeast Oklahoma through Monday night..... ...Slight risk of severe weather for lower Missouri and mid-Mississippi Valleys through Monday night... ...Heavy rainfall possible for the northern Plains through early Monday morning... ...Gulf of Alaska trough expected to move into the Pacific Northwest Monday into Tuesday morning with hot and dry conditions continuing across the Southwest... Deep...slow-moving trough of low pressure over the northern Plains...a well-defined dryline in the southern high Plains and moisture-laden southerly flow off the Gulf of Mexico will set the stage for widespread showers and thunderstorm development from the southern Plains states northward into the Missouri and upper Mississippi Valleys during the next 36 to 48 hours. The persistence of this pattern on Sunday and Monday will allow for the possibility of very heavy rainfall across the northern Plains and the risk of severe thunderstorms for the south central Plains and portions of the Midwest. Please refer to the Storm Prediction Center for the latest information concerning severe weather potential. Out west...a deep trough and moist onshore flow returns to the Pacific Northwest and Northern Rockies early next week. Out ahead of this trough...a quick warm up is expected...followed by below normal temperatures and above average rainfall for much of Washington...northern Oregon...Idaho and western Montana. Little if any relief from the rather warm and dry weather pattern is expected in the Desert Southwest and southern Great Basin with the trough entering the Pacific Northwest early next week. Isolated to scattered showers and a few thunderstorms are possible for Sunday and Monday across the Southeast...the mid-Atlantic states and portions of the Great lakes as a broad warm front and more humid conditions surge northward ahead of the slow-moving low pressure system in the central portion of the country. Vojtesak Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php