Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 421 PM EDT Mon Jun 24 2013 Valid 00Z Tue Jun 25 2013 - 00Z Thu Jun 27 2013 ...Heavy rain and severe weather possible from the Northern Plains to the Middle Mississippi Valley... ...Showers and thunderstorms linger across the Northwest into the northern Rockies as well as into the Southeast... A fairly shallow and weak upper trough over the northwestern U.S. will advance a surface front ahead of it across the northern Rockies and Plains on Tuesday and into the Midwestern states by Wednesday. Showers and thunderstorms are expected to continue to develop over the Northern/Central Plains Monday evening and expand eastward across the Great Lakes and into the Northeast on Tuesday and Wednesday. Some of these storms could produce severe weather as forecast by the Storm Prediction Center. Across the upper Midwest and into the Upper Great Lakes, weak upper level impulses of energy could trigger some heavier rain totals, with the threat for flash flooding, along and ahead of the warm front which extends into this region throughout the day on Tuesday and into the morning hours of Wednesday. Out west, an upper level low and associated surface front currently off the Pacific Northwest coast will bring plenty of moisture to this region throughout the forecast period from northern California, across the Pacific Northwest, and into the northern Rockies. Some of the rain could be heavier at times, especially just ahead of the frontal boundary as it makes its way onshore Tuesday morning. Finally, high pressure over the Atlantic will aid in streaming moisture inland across the southeastern region of the country. Showers and thunderstorms, mostly isolated to scattered in nature, are expected to linger across the area on Tuesday and into Wednesday. Monarski Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php