Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 AM EDT Sun Apr 15 2018 Valid 12Z Sun Apr 15 2018 - 12Z Tue Apr 17 2018 ...There is a slight risk of severe thunderstorms from the Southeast to the Mid-Atlantic with an enhanced risk for the western Carolinas... ...Heavy snow likely from the Upper Midwest to the Upper Great Lakes... ...Rain/freezing rain possible from the Great Lakes eastward to the Northeast... ...Heavy rain possible from parts of the Northeast/Mid-Atlantic to parts of the Tennessee Valley... A robust storm system will continue to spread heavy snow across the Great Lakes region, as well as, strong to severe thunderstorms from the Southeast to the Mid-Atlantic that will be capable of yielding heavy rain. Because of the stark temperature gradient across much of the Ohio and mid-Mississippi Valleys, freezing ran will be possible. Winter Weather Advisories, Winter Storm Warnings and Blizzard Warnings span from southern Minnesota/northern Iowa to Maine. To the South, widespread to numerous showers and thunderstorms will develop along and ahead of the associated front as it tracks from the Ohio Valley into the Southern Mid-Atlantic by Sunday afternoon. Much of the south-central Eastern Seaboard has been included in the slight risk area for severe thunderstorms. Please refer to SPC's convective outlooks for additional information on the expected severe weather. The showers and thunderstorms will move off the Southeast/Southern Mid-Atlantic Coast overnight Sunday. Areas of rain will persist over parts of the Ohio Valleys to Southern New England through Monday morning. Heavy rain will likely occur along the central/northern Appalachian spine and the surrounding areas. WPC has highlighted this region as having a slight risk for excessive rainfall. Meanwhile, a front along the Pacific Northwest Coast will slowly move inland to the Northern Rockies/Great Basin into parts of Southern California by Monday. The snow levels will lower as the boundary moves inland. Rain will begin to move over parts of Northern California by Sunday morning as the higher elevations of the Pacific Northwest will change over to snow. By Sunday evening, rain will move into parts of Central California as snow develops over the higher elevations of Northern California. Overnight Sunday snow will expand into parts of the Great Basin and the Sierras while coastal rain continues over the Pacific Northwest and Northern/Central California Coast. Campbell/Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php