Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 336 AM EDT Sat Jul 13 2013 Valid 12Z Sat Jul 13 2013 - 12Z Mon Jul 15 2013 ...There is a slight risk of severe thunderstorms over of the Northern Plains... ...Heavy rain possible over parts of the Southern Plains... ...Heavy rain possible over parts of the Northern Plains... Upper-level low over Kentucky, Southern Ohio Valley, will move westward to parts of the Southern/Central Plains by Sunday evening. The retrograding system will produce showers and thunderstorms over parts of the Tennessee Valley and the Western Ohio Valley on Saturday. The storm will produce heavier rain and thunderstorms over parts of the Southern/Central Plains on Sunday. In addition, a plume of moisture will also move westward from the Atlantic Coast to Central Gulf Coast/Western Ohio Valley by Sunday. Diurnal heating and orographic forcing will produce shower and thunderstorms from the Atlantic Coast to the Eastern Gulf Coast, waning by Sunday evening. Meanwhile, a quasi-stationary boundary over the Upper Midwest and upper-level energy crossing the the West-Central U.S./Canadian border will trigger showers and thunderstorms over parts of the Upper Mississippi Valley/Upper Great Lakes that will expand roughly southwestward to the Central High Plains/Northern Plains by Sunday. Additionally, weak monsoonal moisture and diurnal heating will produce showers and thunderstorms over parts of the Southwest/Central Rockies and the Great Basin on Saturday and Sunday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php