Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 415 AM EDT Thu May 26 2016 Valid 12Z Thu May 26 2016 - 12Z Sat May 28 2016 ...There is a slight risk of severe thunderstorms over the Southern/Central Plains into parts of the Middle/Lower Mississippi Valley... ...Heavy rain possible over parts of the Lower/Middle Mississippi Valley and the Central/Southern Plains... A deep upper-level trough extending from the Northern High Plains to the Southwest will slowly move eastward to the Plains by Friday evening. Diurnal heating will aid in producing showers and thunderstorms over the Northern Intermountain Region southward to the Great Basin/Southwest eastward to the Northern/Central High Plains on Thursday/Friday afternoon and evening. The areal coverage of the showers and thunderstorms will be at a minimum during the late night and morning time periods. Downstream from the upper-level trough, moisture from the Gulf of Mexico will move northward over the Southern Plains/Lower Mississippi Valley into the Great Lakes/Ohio Valley and into the Upper Mississippi Valley that will continue through Friday evening. Showers and thunderstorms will develop over parts of the Plains and Mississippi Valley into the Great Lakes and Ohio Valley through Friday evening. An area of showers and thunderstorms will develop over the Ohio Valley on late Thursday morning into afternoon that will move into the Northern/Central Appalachians and the Mid-Atlantic by Thursday evening then dissipate. On Friday the showers and thunderstorms will redevelop over the Northern/Central Appalachians and expand into parts of the Northeast and into parts of the Southern Appalachians by Friday evening. In addition, a front will develop over the Pacific Northwest by Thursday evening moving eastward to the Northern Rockies/Great Basin by Friday evening. Rain will develop over parts of the Pacific Northwest Coast on Thursday expanding into parts of the Northern Intermountain Region by Friday evening. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php