Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 408 AM EDT Sun May 22 2016 Valid 12Z Sun May 22 2016 - 12Z Tue May 24 2016 ...There is a slight risk of severe thunderstorms over the Plains... ...Heavy rains possible over parts of the Northern Rockies... A developing upper-level low over the Lower Great Lakes will move roughly southeastward to off the Mid-Atlantic Coast by Monday evening. The system will produce rain over parts of the Lower Great Lakes/Central Appalachians to the Mid-Atlantic/Southern New England on Sunday morning expanding into the Northeast and the Southern Mid-Atlantic by Sunday afternoon through Sunday evening. Overnight Sunday, the rain will continue over parts of the Mid-Atlantic through Monday evening. A second deeper upper-level low over the Northern Rockies will slowly move into Southern Saskatchewan Canada by Monday evening. The storm will produce rain and highest elevation snow over parts of the Pacific Northwest/Northern California eastward to parts of the Northern/Central Rockies through Monday evening. Moisture from the Western Gulf of Mexico will move northward over the Plains that will move into parts of the Upper Mississippi Valley/Upper Great Lakes by Monday. The moisture will aid in producing showers and thunderstorms over the Plains and the Western/Central Gulf Coast through Sunday evening. The showers and thunderstorms will continue over the Plains overnight Sunday returning to the Western Gulf Coast by Monday afternoon into evening. Showers and thunderstorms will move into parts of the Upper Mississippi Valley/Upper Great Lakes, also on Monday afternoon into evening. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php