Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 429 PM EDT Sat Jun 10 2017 Valid 00Z Sun Jun 11 2017 - 00Z Tue Jun 13 2017 ...There is a slight risk of severe thunderstorms over parts of the Upper Great Lakes... ...Heavy rain possible over parts of the Upper Mississippi Valley/Upper Great Lakes... ...Temperatures will be 10 to 25 degrees below average over parts of the Great Basin/Pacific Northwest/California... ...Snow possible at highest elevations of the Cascades/Sierras/Great Basin... An old front over parts of Florida will aid in producing showers and thunderstorms over the area through Sunday morning. On Sunday, moisture from the Gulf of Mexico will move northward over parts of the Lower Mississippi Valley and the Central/Eastern Gulf Coast through Monday. In addition, upper-level impulses will move over the area, too. The moisture,upper-level energy, and diurnal heating will produce showers and thunderstorms over parts of the Lower Mississippi Valley to the Southeast on Sunday and Monday. Meanwhile, a front from the Upper Great Lakes to the Central Plains into the Central Rockies will be quasi-stationary through Monday. Moisture from the Gulf of Mexico will move northward and overrun the boundary producing shower and thunderstorms Overnight Saturday into Monday from parts of the Upper Great Lakes into parts of the Central/Northern Plains and the Central High Plains. Additionally, an upper-level low over the Northwest Coast will will move southeastward to the Great Basin by Monday morning. The system will produce rain over parts of the Pacific Northwest/Northern California into parts of the Northern Rockies. The areal coverage will be much smaller overnight Saturday. The rain will increase on Sunday moving into parts of the Central Rockies and continue through Monday. Areas of snow will develop over the highest elevations of the Northern Rockies through Saturday night. Snow will also develop over the highest elevations of the Cascades by Sunday morning moving into parts of the Sierras by Sunday night and into parts of the Great Basin by Monday morning. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php