Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 PM EDT Wed May 15 2013 Valid 00Z Thu May 16 2013 - 00Z Sat May 18 2013 ...There is a slight risk of severe thunderstorms over Central Texas... A front extending from the Lower Great Lakes westward to the Central Plains will move eastward off the Northeast Coast by Thursday. A second front over the Northern Rockies will move southeastward to the Great Basin/Central Rockies and unite with the lead front over the Central Rockies by Thursday evening. An area of moderate to heavy rain will develop over Maine on Wednesday evening will wane to light rain on Thursday. Showers and thunderstorms will develop over portions of the Mid-Atlantic on Wednesday evening moving off the coast by late Wednesday night. Moisture moving northward out of the Gulf of Mexico will interact with upper-level energy to produce showers and thunderstorms over the Southern Plains/Lower Mississippi Valley will move eastward to the Lower Mississippi Valley/Tennessee Valley by Thursday into Friday. In addition, some of the moisture will overrun the boundary producing showers and thunderstorms over the Ohio Valley into parts of the Mid-Atlantic through Thursday evening. On Friday, rain will develop over parts of the Ohio Valley into parts of the Upper Mississippi Valley. With the second system moving inland, showers and thunderstorms will develop over parts of the Northern/Central Rockies into parts of the Central High Plains on Thursday morning into Thursday evening. With the deep upper-level trough moving over the West Coast will aid in producing light rain over parts of Northern California into the Pacific Northwest, expanding into the Northern Rockies/Northern Plains by Friday morning. Elsewhere, diurnal heating will produce showers and thunderstorms over parts of the Central/southern Rockies on Wednesday evening. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php