Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 339 AM EDT Thu Sep 03 2015 Valid 12Z Thu Sep 03 2015 - 12Z Sat Sep 05 2015 ...Heavy rain possible over parts of the Upper Midwest... ...Heavy rain possible over parts of the Northern Rockies... ...Temperatures will be 10 to 20 degrees above average over parts of the Northern and Central Plains... A front moving southward out of Eastern Canada will advance to the Ohio Valley/Mid-Atlantic Coast before dissipating along the Mid-Atlantic Coast by Friday evening. Showers and thunderstorms will develop along parts the boundary from parts of the Great Lakes to the Northeast that will sink southward to parts of the Mid-Atlantic/Ohio Valley by Friday. Additionally, moisture rich air along the Gulf Coast and upper-level disturbances will aid in producing showers and thunderstorms from the Western Gulf Coast to the Southeast and parts of the Southern Mid-Atlantic Coast through Friday evening. A second front extending from the Northern Plains roughly southwestward to parts of the Great Basin will slowly inch eastward to the Northern Plains/Upper Mississippi Valley while the rest of the boundary trails southwestward to parts of the Great Basin. Showers and thunderstorms will develop near the front from the Northern Rockies to the Upper Mississippi Valley with a maximum areal coverage mainly during the afternoon and late evening hours on Thursday and Friday. Along the Pacific Northwest Coast, onshore flow will come to an end by Thursday evening. Rain associated with the onshore flow will also end by late Thursday night. Upper-level energy moving southward over the Northwest will trigger showers and thunderstorms over parts of the inland portions of the Pacific Northwest and Northern California by Friday evening. Lastly, monsoonal moisture and daytime heating will aid in producing showers and thunderstorms over parts of the Southern/Central Rockies and parts of the Great Basin/Southwest during Thursday and Friday afternoon into late evening. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php