Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 351 AM EDT Mon Jul 21 2014 Valid 12Z Mon Jul 21 2014 - 12Z Wed Jul 23 2014 ...There is a slight risk of severe thunderstorms from parts of the Northern Plains to Upper Great Lakes... ...There is an embedded region of moderate risk of severe thunderstorms over parts of the Northern Plains to parts of the Upper Mississippi Valley... ...Heavy rain possible from parts of the Northern Plains to Upper Great Lakes... A slow moving front extending from the Upper Mississippi Valley to the Northern Intermountain Region will advance eastward to the Upper Great Lakes and southward to the Central Plains by Tuesday evening. High moisture content air will intersect the boundary producing showers and thunderstorms with heavy rain over North Dakota into Minnesota on Monday evening moving into the Upper Great Lakes by Tuesday morning. By Tuesday evening, showers and thunderstorms will extend from the Great Lakes to parts of the Middle Mississippi Valley. Meanwhile, upper-level impulses over the Northern Intermountain Region along with a closed upper-level low will rotate to the Pacific Northwest Coast will produce showers and thunderstorms over parts of the Great Basin/Northern Intermountain Region into parts of the Northern Rockies/Northern High Plains through Tuesday. As the upper-level low closes into the Pacific Northwest, rain will develop over parts of the Northwest on Tuesday. In the meantime, upper-level energy over the Lower Great Lakes will move eastward out over the Western Atlantic triggering showers and thunderstorms over parts the Central/Northern Appalachians on Monday. Additional upper-level energy over the Southeast/Central Gulf Coast will produce showers and thunderstorms from the Central Gulf Coast to the Southeast/Southern Mid-Atlantic on Monday. On Tuesday the showers and thunderstorms will become more confined to the Southeast and immediate Central Gulf Coast and Florida. Elsewhere, weak monsoonal moisture and diurnal heating will produce showers and thunderstorms over portions of the Southern Rockies/High Plains during the late afternoon and evening hours on Monday and Tuesday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php