Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 326 AM EDT Fri Aug 15 2014 Valid 12Z Fri Aug 15 2014 - 12Z Sun Aug 17 2014 ...Heavy rain possible over parts of the Middle Mississippi Valley... ...Temperatures will be near 10 degrees below average over parts of the Lower Great Lakes... A weak boundary over the Middle Mississippi Valley will be the focus for showers and thunderstorms over the region as high moisture content air and multiple upper-level disturbances also move over the area through Saturday. In addition, another weak front along the Gulf Coast along with upper-level impulses will produces showers and thunderstorms over parts of the Gulf Coast and Florida through Saturday evening. Meanwhile, a weakening upper-level low over the Pacific Northwest will open as the energy moves to the Northern High Plains by Saturday. The energy will trigger showers and thunderstorms over parts of the Northern Rockies on Friday moving to the Northern Plains by Saturday. Additionally, a front moving southward out of Central Canada will move into the Upper Midwest Friday night into Saturday morning moving into parts of the Great Lakes by Saturday evening. Showers and thunderstorms will develop along and ahead of the boundary over parts of the Upper Mississippi Valley Friday evening moving into the Lower Great Lakes while extending westward into parts of the Middle Missouri Valley by Saturday evening. Rain will also develop over parts of Northern New England on Saturday evening, too. Elsewhere, monsoonal moisture and diurnal heating will produce showers and thunderstorms over parts of the Southern/Central Rockies and parts of the Southern High Plains on Friday and Saturday during the late afternoon and evening. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php