Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 344 AM EDT Fri Aug 22 2014 Valid 12Z Fri Aug 22 2014 - 12Z Sun Aug 24 2014 ...There is a slight risk of severe thunderstorms over portions of the Central Rockies... ...Heavy rain over the Northern Rockies/High Plains and parts of the Northern Plains... ...Temperatures will be 10 to 15 degrees below average over parts of the Northern Rockies/High Plains... An upper-level trough over the Pacific Northwest will move eastward to the Northern High Plains by Saturday evening. The energy in combination with upslope flow and a moisture connection from the Upper Midwest will aid in producing showers and thunderstorms over parts of the Northern Rockies/High Plains on Friday. The showers and thunderstorms will expand into the Northern Plains/Upper Mississippi Valley while increasing to heavy rain by Saturday evening. Meanwhile, a persistent boundary extending from the Mid-Atlantic roughly westward to the Central Plains will have high moisture content air pooling along the boundary through Saturday. The boundary will provide a focus for showers and thunderstorms from parts of the Mid-Atlantic to the Central Plains that will taper off to parts of the Southeast/Tennessee Valley by Saturday evening. Elsewhere, upper-level energy over the Southwest will move northeastward to the Northern Plains by Saturday. The energy will trigger showers and thunderstorms over parts of the Southern/Central Rockies that will expand into parts of the Southern/Central High Plains by Friday evening that will taper off to parts of the Central Rockies by Saturday evening. In addition, showers and thunderstorms will develop over parts of Florida Friday into Saturday morning. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php