Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 415 AM EDT Wed May 25 2016 Valid 12Z Wed May 25 2016 - 12Z Fri May 27 2016 ...There is a slight risk of severe thunderstorms from the Southern Plains to the Upper/Middle Mississippi Valley and parts of the Central/Northern Plains... ...Heavy rain possible over parts of the Southern Plains... ...Heavy rain possible over parts of the Central Plains/Middle Mississippi Valley... A deep upper-level trough over the western third of the country will move eastward to the Plains/Rockies by Thursday evening. Under the upper-level trough, showers and thunderstorms will develop from parts of California to the Northern Intermountain Region/Great Basin and the Northern/Central Rockies by Wednesday evening with daytime heating contributing to the areal extend of the storms. On Thursday, the showers and thunderstorms will extend from the Northern/Central High Plains to the Great Basin/Northern Intermountain Region with daytime heating contributing to the areal extend. Downstream from the upper-level trough, moisture from the Gulf of Mexico will stream northward over the Southern Plains into the Middle Mississippi Valley and the Upper Midwest that will extend into the Great Lakes/Ohio Valley by Thursday evening. Showers and thunderstorms will develop over parts of the Plains and the Mississippi Valley that will expand into parts of the Great Lakes/Ohio Valley by Wednesday evening. By Thursday morning, the showers and thunderstorms will develop over parts of the Upper Mississippi Valley/Upper Great Lakes southwestward into the Southern Plains and over the Great Lakes/Ohio Valley will expand eastward into parts of the Northern/Central Appalachians by Thursday evening. In addition on Thursday, a front will develop over the Pacific Northwest and move eastward to the Northern Intermountain Region by Thursday evening as upper-level energy moves onshore over the Northwest. Rain will develop over parts of the Pacific Northwest Coast on Thursday as the energy moves inland. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php