Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 335 AM EDT Wed Aug 21 2013 Valid 12Z Wed Aug 21 2013 - 12Z Fri Aug 23 2013 ...There is a slight risk of severe thunderstorms over portions of the Upper Great Lakes/Upper Mississippi Valley... ...Temperatures will be 10 to 15 degrees above average over parts of the Upper Great Lakes... The quasi-stationary front over the Southeast/Central Gulf Coast will dissipate on Wednesday. With the deep moisture in place over the region, showers and thunderstorms will develop over the Southeast, Tennessee Valley, Central Appalachians, and the Central Gulf Coast through Thursday. Meanwhile, a front over the Upper Midwest will move southeastward to the Northeast, Ohio Valley, and the Central Plains by Thursday evening. Showers and thunderstorms will develop along and ahead of the boundary from the Upper Great Lakes/Upper Mississippi Valley advancing to the Northeast, Mid-Atlantic, and the Ohio Valley by Thursday evening. Elsewhere, upper-level energy off the Central California Coast will move inland to Northern California by Thursday. The energy will produce showers and thunderstorms over parts of East-Central California/Great Basin moving northward into parts of the Pacific Northwest/Northern Rockies by Thursday evening. In addition, diurnal heating and monsoonal moisture will trigger showers and thunderstorms over parts of the Southern/Central Rockies and parts of the Southwest/Great Basin through Thursday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php