Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 347 AM EDT Sat Jul 15 2017 Valid 12Z Sat Jul 15 2017 - 12Z Mon Jul 17 2017 ...Slight risk of severe thunderstorms over parts of the Upper Mississippi Valley/Upper Great Lakes... ...Heavy rain possible over parts of the Carolinas and Central High Plains... A front extending from the Southern Mid-Atlantic to the Lower Mississippi Valley will slowly weaken while being quasi-stationary through Sunday evening. Very moist air south of the boundary and associated upper-level energy will aid in producing showers and thunderstorms from parts of the Southern Mid-Atlantic/Southeast westward to the Southern Plains through Sunday evening, too. A second front over the Upper Mississippi Valley to the Northern High Plains will advance eastward to the Northeast into the Ohio Valley then northwestward to the Northern Plains by Sunday. Showers and thunderstorms will develop along and ahead of the boundary over parts of the Upper Mississippi Valley into the Northern Plains that will move eastward to the Northeast/Ohio Valley to the Middle Mississippi Valley on Sunday evening into Monday. In addition, a third front will move from the Pacific Northwest eastward to the Northern High Plains southwestward into parts of the Great Basin by Sunday evening. Showers and thunderstorms will also develop along and ahead of the boundary over parts of the Northern Rockies/ Northern High Plains that will move to the Northern High Plains southwestward into parts of the Great Basin by Sunday into Monday. Additionally, monsoonal moisture along with upper-level energy and daytime heating will aid in producing showers and thunderstorms over parts of Southern/Central Rockies into parts of the Central High Plains and the Southwest through Sunday evening into Monday. Elsewhere, upper-level energy over the Northeast will move out over the Western Atlantic by Saturday evening. The energy will aid in producing showers and thunderstorms over parts of the Northeast through late Saturday night. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php