Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 437 PM EDT Sun Aug 18 2013 Valid 00Z Mon Aug 19 2013 - 00Z Wed Aug 21 2013 ...Unsettled weather will continue to focus along a frontal boundary stretched from the Central Gulf Coast to the Carolinas... ...Severe storms will be possible over portions of the Northern Plains... Unsettled weather will continue to focus along a frontal boundary stretched from the Central Gulf Coast to the Carolinas. In general...the chance for any organized activity should diminish as the front gradually weakens during the next few days...but a rich plume of Gulf moisture streaming northward over the boundary will keep areas of moderate to heavy rains a possibility across the Florida Panhandle. Much of the Southeastern U.S. has already recorded plenty of rain the past few days...making any additional rainfall a threat for flash flooding. After a day of dreary weather...conditions should slowly be clearing out over southern New England and the northern Mid-Atlantic states as a surface low tracks out into the Atlantic. There will still be a chance for showers and thunderstorms farther inland along the Appalachians on Monday...but by Tuesday...the region should be precipitation free. A weak frontal boundary pushing through the northern tier will trigger some isolated convection as it crosses the Northern Plains and Upper Midwest Sunday night into Monday. Although any developing storms are not expected to carry a heavy rain threat...they will have the capability to produce severe weather. The front is expected to dissipate before it has the chance to move through the Upper Great Lakes on Tuesday. Out west...a closed low setting up off the California coast will be bringing moisture into the Central Great Basin...Southwest...and Central/Southern Rockies. The moisture...in combination with afternoon heating...should foster additional days of scattered showers and thunderstorms across the region. Farther north...energy streaking through aloft could help produce some shower activity over the extreme Northwestern U.S....but any heavy precipitation should stay north of the Canadian border. Gerhardt Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php