Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 333 AM EDT Sun Aug 18 2013 Valid 12Z Sun Aug 18 2013 - 12Z Tue Aug 20 2013 ...There is a slight risk of severe thunderstorms over parts of the Northern Plains... ...Heavy rain possible over parts of the Central Gulf Coast... ...Temperatures will be 10 plus degree below average from parts of the Mid-Atlantic to the Southern Appalachians/Tennessee Valley... A quasi-stationary front extending along the Southeast/Mid-Atlantic Coast southwestward to the Eastern/Central Gulf Coast will trigger showers and thunderstorms over parts of the Mid-Atlantic/Southeast to the Central/Eastern Gulf Coast and parts of the Tennessee Valley through Monday evening. In addition, a weakening front over the Northern Plains will produce showers and thunderstorms over the area through late Sunday night. Additionally, onshore flow along the Pacific Northwest Coast will trigger light rain over the region on Sunday morning. Elsewhere, diurnal heating and monsoonal moisture will produce showers and thunderstorms over parts of the Southern/Central Rockies and the Southwest/Great Basin on Sunday and Monday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php