Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 406 AM EDT Fri Jul 18 2014 Valid 12Z Fri Jul 18 2014 - 12Z Sun Jul 20 2014 ...Heavy rain possible over parts of the Tennessee Valley... ...Heavy rain possible along the Central Gulf Coast... ...Temperatures will be 10 to near 20 degrees below average from parts of the Southern/Central Plains to the Southern/Central Appalachians... A quasi-stationary front along the Gulf Coast and the Southeast Coast will have a wave of low pressure lift northeastward from Eastern Texas to Southern Appalachians by Saturday evening. Moisture from the Gulf of Mexico will flow northward overrunning the boundary producing showers and thunderstorms with moderate rain over parts of the Lower Mississippi Valley/Western Gulf Coast moving to the Eastern Gulf Coast/Southeast/Southern Ohio Valley and the Lower Great Lakes by Saturday. Rain will also develop over parts of the Central/Southern Appalachians to parts of Lower Mississippi Valley lifting northeastward into parts of the Ohio Valley by Friday evening into Saturday. Another front over the Northern High Plains/Northern Plains will move eastward to the Upper Mississippi Valley before lifting northward as a warm front by Saturday. Showers and thunderstorms will develop along and ahead of the boundary over the Northern Plains on Friday afternoon into evening moving to parts of the Upper Great Lakes by Saturday evening. In addition, upper-level impulses will produce areas of showers and thunderstorms over parts of the Southern/Central Rockies and the Southern High Plains through Saturday. Elsewhere, upper-level energy coming onshore over the Pacific Northwest will produce rain along the U.S./Canadian border over the Northwest on Saturday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php