Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 327 AM EDT Wed Sep 23 2015 Valid 12Z Wed Sep 23 2015 - 12Z Fri Sep 25 2015 ...Flash flooding possible across portions of the central plains and Upper Midwest... ...Showers and thunderstorms will increase over the coastal southeastern U.S. over the next couple days... A west-east oriented frontal boundary will linger across the northern plains/Upper Midwest today as an upper-level disturbance moves across the region. These features will combine to produce an environment favorable for the development of numerous showers and thunderstorms today through tonight. Heavy rainfall amounts of 1 to 3 inches are forecast to fall across these areas, and flash flooding is possible. Scattered thunderstorms will persist along the front Thursday afternoon, but activity should be much less widespread than today. An area of low pressure over the Atlantic Ocean will drift slowly westward toward the Southeast U.S. coastline over the next couple days. Scattered showers and thunderstorms are possible along the coast today, but these may begin to increase in coverage on Thursday and Friday as the surface low and an associated frontal boundary draw closer to the coast. A Pacific frontal system will approach the northwestern U.S. on Thursday, with showers possible across coastal areas as soon as Wednesday night. Showers will persist through Thursday night across coastal areas as well as the Cascades, before the front begins to push inland very early on Friday. Temperatures across the contiguous U.S. will be above average for many areas over the next couple days. The Intermountain West will see afternoon high temperatures 10 to 15 degrees above average; while areas from the Midwest to the Northeast will see temperatures 5 to 10 degrees above average. Ryan Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php