Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 403 AM EDT Sat Mar 15 2025 Valid 12Z Sat Mar 15 2025 - 12Z Mon Mar 17 2025 ..Heavy snow over the Cascades/Northern Intermountain Region and Upper Mississippi Valley on Saturday; light to moderate snow over the Upper Great Lakes on Sunday... ...A Moderate Risk of excessive rainfall over parts of the Ohio/Tennessee Valleys, Lower Mississippi Valley, and Southern Appalachians on Saturday... ...There is a High Risk of severe thunderstorms over parts of the Lower Mississippi/Tennessee Valleys and the Southeast on Saturday... ...A Slight Risk of severe thunderstorms over the Mid-Atlantic to the Southeast on Sunday... A front extending from the Upper Mississippi Valley to the Lower Mississippi Valley/Western Gulf Coast will move eastward to the East Coast by Monday. The storm will produce showers and thunderstorms from the Great Lakes to the Lower Mississippi Valley and Southeast on Saturday. However, showers and severe thunderstorms will develop over parts of the Ohio Valley to the Gulf Coast. Therefore, the SPC has issued a High Risk (level 5/5) of severe thunderstorms over parts of the Lower Mississippi/Tennessee Valleys and the Southeast through Sunday morning. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and several tornadoes. There is an additional threat of F2- EF5 tornadoes over parts of the Lower Mississippi /Tennessee Valleys, the Central Gulf Coast, and the Southeast. Furthermore, there is also an added threat of severe thunderstorm wind gusts 65 knots or greater and hail, two inches or greater over parts of the Lower Mississippi /Tennessee Valleys, the Central Gulf Coast, the Southeast, and Southern Appalachians. Furthermore, on Saturday, heavy rain will occur over parts of the Ohio/Tennessee Valleys, Lower Mississippi Valley, and Southern Appalachians. Therefore, the WPC has issued a Moderate Risk (level 3/4) of excessive rainfall over parts of the Ohio/Tennessee Valleys, Lower Mississippi Valley, and Southern Appalachians through Sunday morning. Numerous flash flooding events are possible and many streams may flood, potentially affecting larger rivers. In addition, heavy snow will develop over parts of the Upper Mississippi Valley on Saturday and light to moderate snow over the Upper Great Lakes on Sunday. Also, rain will develop over parts of the Lower Great Lakes and Ohio Valley on Sunday. Moreover, as the front moves into the East Coast on Sunday, showers and thunderstorms will develop from the Lower Great Lakes/Northeast to the Southeast. Further, the system will produce severe thunderstorms over parts of the Mid-Atlantic to the Southeast. Therefore, the SPC has issued a Slight Risk (level 2/5) of severe thunderstorms over parts of the Mid-Atlantic to the Southeast Sunday through Monday morning. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a few tornadoes. Meanwhile, on Saturday, upper-level energy extending from the Pacific Northwest to the Southwest will produce coastal rain and higher-elevation snow over parts of the Pacific Northwest and Northern California. The snowfall will be heavy over the Cascades and Northern Intermountain Region. Lighter snow will develop over parts of the Central/Southern Rockies and rain at the lower elevations over the Southwest. The snow will end over the Central/Southern Rockies by Sunday morning. Moreover, on Sunday, a front will move onshore over the Pacific Northwest and inland to the Northern Rockies by Monday. Coastal rain and higher-elevation snow will continue over the Pacific Northwest and Northern Intermountain Region, with rain at lower elevations on Sunday. By Sunday afternoon, the southern part of the boundary will move onshore over parts of Northern California. Rain and higher-elevation snow will develop over parts of Northern/Central California. Ziegenfelder Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php