772 FXUS01 KWBC 190743 PMDSPD Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 241 AM EST Fri Dec 19 2025 Valid 12Z Fri Dec 19 2025 - 12Z Sun Dec 21 2025 ...Heavy snow over parts of the UP and northern LP of Michigan and Lakes Erie/Ontario coastline... ...Heavy snow for the Cascades and Northern Rockies... ...There is a Slight Risk of excessive rainfall over parts of the Pacific Northwest on Friday... A front extending from the Lower Great Lakes to the Southeast will move eastward off the East Coast by Friday evening. The system will produce rain over parts of the Northeast and Mid-Atlantic through Friday evening. Upper-level energy associated with the system will produce light to moderate snow over the UP and northern LP of Michigan and parts of Ohio/Central Appalachians/Northeast through Saturday morning. Moderate to heavy snow will develop downwind from Lakes Erie/Ontario also through Saturday morning. See the WPC Heavy Snow Discussion for details and amounts. Meanwhile, a front over the Northern Intermountain Region and the Pacific Northwest will move eastward into the Northeast, Mid-Atlantic, Lower Mississippi Valley, and Southern Plains by Sunday. The storm will produce rain and higher-elevation snow across the Pacific Northwest, Northern Intermountain Region, and Northern Rockies through Sunday. Rain and the highest-elevation snow will develop across parts of California through Sunday. In addition, a plume of moisture will stream into Northern California, producing heavy rain. Therefore, the WPC has issued a Slight Risk (level 2/4) of excessive rainfall through Saturday morning. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, small streams, and burn scars being the most vulnerable. Along the associated warm front over the Northern Plains, areas of rain/freezing rain will develop through Saturday morning. Light to moderate snow will also develop over parts of the Northern Plains/Upper Mississippi Valley through Saturday morning. As the boundary moves over the Great Lakes, moderate to heavy snow will develop over parts of the Upper Peninsula of Michigan from Saturday into Sunday morning. From Saturday afternoon to Sunday morning, light snow will return downwind from the Great Lakes and into parts of the Northeast. Overnight Friday, a wave of low pressure will develop along the front over the Central Rockies, producing light snow over the region through Sunday. Along with the system, light rain will develop over parts of the Great Basin from Friday into Sunday Ziegenfelder Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php $$