Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 425 AM EDT Sat May 20 2017 Valid 12Z Sat May 20 2017 - 12Z Mon May 22 2017 ...There is a slight risk of severe thunderstorms over parts of the Lower Mississippi Valley into the Central Ohio Valley... ...There is a slight risk of severe thunderstorms over parts of southern Texas... ...Heavy rain possible over parts of the Southeast into parts of the Southern/Central Appalachians... Low pressure over the Middle Mississippi Valley will lift northward to Western Ontario by Sunday evening. Showers and thunderstorms will develop along and ahead of the associated cold front from parts of the Middle/Lower Mississippi Valley to the Southern Plains that will move lift northward into the Great Lakes overnight Saturday. In addition, the showers and thunderstorms will move eastward to the Lower Great Lakes to the Southeast and along the Gulf Coast to the Lower Rio Grande Valley by Sunday evening. Additionally, showers and thunderstorms will develop over parts of the Southeast into parts of the Central Appalachians and the Southern Mid-Atlantic through Sunday. Furthermore, rain will develop over parts of the Central Plains/Middle Missouri Valley on Saturday that will lift northward into the Northern Plains eastward to the Upper Great Lakes by Saturday evening into Sunday evening. Meanwhile, upper-level energy over the Pacific Northwest will move southeastward to the Eastern Great Basin by Sunday evening into Monday. Rain will develop over parts of the Northwest into parts of the Northern Rockies on Saturday. By Saturday evening, an area of embedded showers and thunderstorms will develop over parts of the Northern Rockies/Northern High Plains into parts of the Central Rockies that will diminish to an area over parts of the Great Basin/Northern Intermountain Region by Sunday morning. The region of embedded showers and thunderstorms will redevelop over parts of the Central Rockies/Eastern Great Basin into parts of the Northern to Southern High Plains by Sunday evening. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php