Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 336 PM EDT Thu Sep 03 2015 Valid 00Z Fri Sep 04 2015 - 00Z Sun Sep 06 2015 ...Severe thunderstorms possible on Friday across portions of the northern plains and Upper Midwest... ...Above average temperatures expected for the eastern two-thirds of the U.S. through Saturday... A cold front will extend from the northern plains into the northern Intermountain West by this evening before becoming nearly stationary tonight -- allowing several waves of low pressure to move along the front through Saturday. This front will result in scattered to numerous showers and thunderstorms tonight from the northern Intermountain West eastward into the northern plains. On Friday, the front will bring scattered to numerous showers and thunderstorms from the northern plains to portions of the Upper Midwest. Some of these thunderstorms in the northern plains/Upper Midwest may become severe -- as highlighted by a slight risk of severe thunderstorms in the Day 2 Convective Outlook from the Storm Prediction Center. Additional showers and thunderstorms will continue on Friday farther west, across much of the northern Intermountain West, as the frontal boundary remains nearly stationary across the region. The frontal boundary will move little on Saturday, with showers and thunderstorms in the forecast once again from much of the northern Intermountain West eastward to the Upper Midwest. Across the southwestern U.S., monsoonal moisture will keep scattered afternoon and evening showers and thunderstorms in place across the Four Corners region through Saturday. Showers and thunderstorms should be the most numerous in areas of terrain. A weak cold front will move southward across the Mid-Atlantic states and Great Lakes this evening, bringing scattered showers and thunderstorms. This front will continue to bring scattered showers and storms to the Mid-Atlantic on Friday before the front dissipates on Saturday. North of this front, a drier and more comfortable air mass will move into much of the Northeast and Mid-Atlantic regions. Finally, above average temperatures will remain predominant across the eastern two-thirds of the country, as high pressure at the mid and upper-levels of the atmosphere remains in place. Afternoon high temperatures will be 5 to 10 degrees above average over most of the eastern two-thirds of the country. Across portions of the Midwest, temperatures may rise to 10 to 15 degrees above average. The Mid-Atlantic may see some cooler temperatures by Saturday as air originating over the cool waters of the Atlantic moves into the region behind the cold front. Temperatures on Saturday across the Mid-Atlantic may be 5 degrees below average. Ryan Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php