Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 445 AM EDT Sat Apr 22 2017 Valid 12Z Sat Apr 22 2017 - 12Z Mon Apr 24 2017 ...There is a slight risk of severe thunderstorms over the Lower Mississippi Valley and Tennessee Valley... ...Heavy rain possible from parts of the Mid-Atlantic to the Tennessee Valley/Southern Appalachians... ...Snow is possible for parts of the Northern Rockies and Cascades... Low pressure over the Lower Mississippi Valley will move northeastward to the Southeast/Southern Appalachians by Sunday morning and to near the Southeast Coast by Sunday evening. The system will produce showers and thunderstorms from parts of the Mid-Atlantic to the Middle/Lower Mississippi Valley and parts of the Southern Plains that will move to the Southeast/Southern Appalachians and continuing eastward to the Mid-Atlantic Coast by Sunday evening. Meanwhile, low pressure over Southeastern Canada will slowly dissipate by Sunday morning. The system will aid in producing rain over parts of the Northeast that will end by Sunday morning. A front over South-Central Canada will move southward into the Great Lakes to the Northern High Plains by Sunday evening. Rain will develop over parts of Northern Plains/Upper Mississippi Valley by Saturday evening and expanding into the Upper Great Lakes by Sunday morning. The rain will wane to an area over the Upper Mississippi Valley by Sunday evening. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php