Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 343 AM EDT Wed Jul 18 2018 Valid 12Z Wed Jul 18 2018 - 12Z Fri Jul 20 2018 ...There is a slight risk of severe thunderstorms over parts of the Central Plains... ...Heavy rain possible over parts of the Upper Mississippi and the Middle Missouri Valleys... ...Heavy rain possible over parts of the Southeast Coast and the Eastern Gulf Coast... A quasi-stationary front extending from the Southern Mid-Atlantic into parts of the Southern Plains will slowly dissipate over the Southern Plains/Lower Mississippi Valley by Thursday evening, while the boundary continues over the Southeast. Showers and thunderstorms will develop along and near the front from the Southern Mid-Atlantic Coast to parts of the Lower/Middle Mississippi Valley and parts of the Southern Plains that will end over the Lower/Middle Mississippi Valley and Southern Plains overnight Wednesday. Showers and thunderstorms will continue over parts of the Southern Mid-Atlantic/Southeast westward to the Tennessee Valley through Thursday evening. Meanwhile, upper-level energy over Northern Plains will move eastward to the Upper Mississippi Valley by Thursday evening. The energy will trigger showers and thunderstorms over parts of the Northern/Central High Plains and the Northern Plains that will move into parts of the Northern/Central Plains by Wednesday evening. The showers and thunderstorms will continue to move eastward into the Upper/Middle Mississippi Valley by Thursday evening. Additional upper-level energy will aid in producing showers and thunderstorms over parts of the Central Plains Thursday afternoon into evening. In addition, monsoonal moisture and daytime heating will aid in developing showers and thunderstorms over parts of the Southwest/Great Basin and Central/Southern Rockies through Thursday evening. The greatest areal coverage of the showers and thunderstorms will be during the late afternoon into the late evening on Wednesday and Thursday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php