Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 228 AM EDT Sat Aug 30 2014 Valid 12Z Sat Aug 30 2014 - 12Z Mon Sep 01 2014 ...Central and Northern Plains and Upper Mississippi Valley could see a threat of severe weather on Sunday... ...A large area of showers and thundershowers will affect the Gulf Coast and Lower Mississippi Valley on Saturday and spread eastward on Sunday... ...Warmer and more humid conditions will spread eastward across much of the East while cooler temperatures cover much of the West on Sunday and Monday, except for hot and dry for the Southwest... A cold front will swing eastward from the northwestern states on Saturday and reach the Northern Plains on Sunday. Southerly winds ahead of the front will bring heat and moisture northward and could help set up the potential for severe thunderstorms, hail and a few tornadoes later on Sunday from Kansas and Nebraska into Iowa and Minnesota. A weak upper trough over the Southern Plains with flow off the Gulf of Mexico will combine to produce an area of heavy showers and thundershowers from eastern Texas and Louisiana across the Lower Mississippi Valley into part of the Southeast on Saturday. Another area of rainfall now across the Upper Mississippi Valley will spread eastward across the Midwest as well. A general increase of moisture will occur along the Mississippi Valley on Saturday and spread eastward on Sunday with showers and thundershowers from the Tennessee and Ohio Valleys toward the Appalachians into the western portions of the Middle Atlantic states and Northeast. As high pressure moves eastward off the Northeast coast, warmer and more humid conditions will return across much of the East Coast and will continue through Labor Day with scattered thundershowers and temperatures near 90 degrees. Meanwhile, cooler conditions will cover much of the Northwest and Northern Rockies and then move eastward toward the Midwest by Monday. Hot and dry conditions will remain over the Desert Southwest where temperatures will exceed 100 degrees. Kocin Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php