Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 352 AM EDT Sat Jun 21 2014 Valid 12Z Sat Jun 21 2014 - 12Z Mon Jun 23 2014 ...There is a slight risk of severe thunderstorms from the Middle Missouri Valley to the Western Ohio Valley and over parts of the Carolinas... ...Heavy rain possible over parts of the Central Plains into Iowa and along the Carolina Coast... A quasi-stationary boundary extending from the Mid-Atlantic to the Upper Mississippi Valley will slowly sink southward into the Southeast, while a second front will merge with the western end of the stationary boundary by Sunday. Low pressure over the Mid-Atlantic will move southeastward to the Carolina Coast by Saturday evening, then move off the Coast on Sunday. The area of low pressure will produce showers and thunderstorms over the Mid-Atlantic/Central Appalachians/Eastern Ohio Valley that will move into the Carolinas by Saturday evening and off the Coast by Sunday evening. In addition, an impulse of upper-level energy moving along the front will trigger showers and thunderstorms over parts of the Middle Mississippi Valley into the Ohio Valley on Saturday. A second front over the Northern High Plains/Great Basin will move eastward to the Upper Mississippi Valley/Central Rockies by Sunday. The boundary will be mostly dry on Saturday morning. The front will intersect moisture form the Gulf of Mexico that is moving northward over the Plains producing showers and thunderstorms over the Northern/Central High Plains that will move into the Upper Mississippi Valley/Central Plains overnight Saturday and into the Upper Great Lakes/Ohio Valley by Sunday morning. Showers and thunderstorms will reignite over the Central/Southern Plains into the Ohio Valley by Sunday evening. In addition, an upper-level impulse over the Northern High Plains will aid in producing showers and thunderstorms over the Northern High Plains on Sunday morning that will sink southward into Central High Plains/Central Rockies by Sunday evening. Meanwhile, upper-level energy over Western Texas will slowly move to Central Texas by Sunday. Showers and thunderstorms will develop over West Texas on Saturday that will move to Central Texas by Sunday morning. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php