Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 328 PM EDT Fri Jul 18 2014 Valid 00Z Sat Jul 19 2014 - 00Z Mon Jul 21 2014 ...Heavy rain possible from the central Gulf Coast to the southern/central Appalachians... ...Temperatures remain below normal from the southern Plains to Mid-Atlantic... A lingering quasi-stationary boundary draped along the Southeast and Gulf of Mexico coastlines remains the culprit for wet weather throughout the weekend. Moisture from the Gulf of Mexico will continue to stream northward, overrunning the boundary, to produce numerous showers and thunderstorms for the Gulf Coast and Southeastern states to the Appalachians and parts of the Ohio Valley. The heaviest and most organized of the precipitation is expected overnight Friday and into Saturday from the central Gulf Coast to the central Appalachians. The continuous stream of moisture off the warm Gulf, combined with the practically stationary boundary, could lead to a threat for flash flooding, especially along the central Gulf Coast states where heavy rainfall and flash flooding is already occurring. For the remainder of the country, the weather remains rather quiet. A weakening front moving across the Upper Midwest may produce a few showers or thunderstorms as it skirts eastward, while energy moving into western Canada could bring some light rainfall to the higher terrain of the Pacific Northwest. For the central U.S., and into the Mid-Atlantic/Northeast, temperatures remain pleasant and very comfortable, with values anywhere from 5 to 20 degrees cooler than normal for this time of the year. Monarski Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php