Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 359 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. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php