Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 406 PM EDT Sat May 10 2014 Valid 00Z Sun May 11 2014 - 00Z Tue May 13 2014 ...There is a slight risk of severe thunderstorms over pats of the Middle Mississippi Valley... ...Heavy snow over parts of the Central Rockies/High Plains... ...Heavy rain possible from parts of the Central Plains to the Upper Mississippi Valley and also over parts of the Southern Plains... ...Temperatures will be 15 to 30 degrees below average over parts of the Central Rockies/High Plains... A quasi-stationary front will oscillate south then north from the Northeast to the Middle Mississippi Valley through Monday. Showers and thunderstorms will develop along the boundary from the Northern Appalachians to the Central Appalachians/Tennessee Valley on Saturday before ending by Sunday morning. Another area of showers and thunderstorms will develop over parts of the Upper Midwest and move southward to Middle Mississippi Valley by Sunday morning. On Sunday, moisture from the Gulf of Mexico will move northward over the Mississippi Valley bringing abundant moisture to the area aiding in the development of showers and thunderstorms with moderate to heavy rain over parts of the Middle Mississippi Valley into the Great Lakes on Sunday evening into Monday. Moderate to heavy rain will develop over parts of the Upper Mississippi Valley into the Upper Great Lakes Sunday into Monday. Meanwhile, upper-level energy over the West Coast will advance eastward to the Southern Rockies by Monday. The system will produce snow over parts of the Northern/Central Rockies that will develop into moderate to heavy snow over the Central Rockies/High Plains and parts of the Great Basin on Sunday. Rain will also develop over parts of the lower elevations, too. This storm will also tap into the moisture from the Gulf of Mexico aiding in the development of moderate to heavy rain over parts of the Central Plains on Sunday moving into parts of the Northern Plains by Monday morning. Also by Monday morning, the snow will taper off to light snow over parts of the Central Rockies. Additionally, showers and thunderstorms will develop along and ahead of the associated front over the Central/Southern Plains Sunday evening into Monday. Elsewhere, showers and thunderstorms will also develop over parts of the Central Gulf Coast on Sunday and over parts of the Southeast on Saturday evening. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php