Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 308 PM EST Fri Jan 12 2024 Valid 00Z Sat Jan 13 2024 - 00Z Mon Jan 15 2024 ...Heavy snow from the Great Lakes to the Northeast and from the Cascades/Sierra Nevada Mountains to the Central Rockies... ...There is a Slight Risk of excessive rainfall from the northern Mid-Atlantic to Southern New England on Friday and over parts of the Pacific Northwest to Northern California on Saturday... ...There is a Slight Risk of severe thunderstorms over parts of the Central Gulf Coast, Southeast, and southern Mid-Atlantic... A major winter storm over the Great Lakes/Ohio Valley will move northeastward into Eastern Canada by Saturday. The conditions will deteriorate rapidly on Friday in the Midwest as heavy snow continues to spread across the Upper Midwest. Snowfall rates of 1 to locally 2 inches per hour will lead to hazardous travel conditions over much of the region. In addition, blizzard conditions are likely to occur, with strong winds through Friday night over the Midwest and Great Lakes as the storm system rapidly strengthens. Blizzard conditions are likely, particularly in exposed areas. Travel will become dangerous to impossible with whiteout conditions and power outages are possible. Furthermore, lake-effect snow will persist downwind from the Great Lakes through Sunday evening. While the larger snow area will diminish on Saturday, the arrival of colder air will generate heavy snow downwind of the Great Lakes through Sunday evening and later. Whiteout conditions in the lake-effect snow bands are expected. Moreover, severe storms will develop over the Southeast. Severe storms will be possible in the South Friday and damaging gusts may occur outside of thunderstorms. Therefore, the SPC has issued a Slight Risk of severe thunderstorms over parts of the Central Gulf Coast, Southeast, and southern Mid-Atlantic through Saturday morning. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a few tornadoes. Additionally, heavy rain will develop over the Mid-Atlantic and Northeast Friday night and Saturday, leading to renewed rises in rivers and streams and possible flooding. Moderate to isolated major coastal flooding, with significant impacts, is likely in the Mid-Atlantic and Northeast Saturday. Therefore, the WPC has issued a Slight Risk of excessive rainfall over parts of the northern Mid-Atlantic to Southern New England. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, and small streams the most vulnerable. In the wake of the storm, cold air will descend from Western Canada across the Northern Intermountain Region to the Central/Southern Plains and Middle Mississippi Valley. A bitter cold surges south and affects most of the U.S. The first significant Arctic outbreak of the winter has arrived across the Northwest and Northern Plains and will spread south through early next week. Numerous daily cold records are forecast. Moreover, dangerously cold wind chills are expected. Sub-zero wind chills will affect much of the U.S. and reach into portions of the South. Wind chills this weekend will fall below negative 30 degrees from the Northern Rockies to northern Kansas and into Iowa. Values may drop as low as negative 50 degrees from Montana across the western Dakotas. These extreme apparent temperatures will pose a risk of frostbite on exposed skin and hypothermia. Travelers will need to have a cold survival kit if you must travel. Further, heavy snow develops in the West on Friday and Saturday.As arctic air will gradually lower snow levels in time for the arrival of another storm system in the West. The snow levels will lead to snow and considerable impacts in valleys in Oregon, Idaho, Nevada, and Utah, including the Portland, Boise, and Salt Lake City metro areas. Significant freezing rain is likely on Saturday in northwestern Oregon. Furthermore, areas of snow, sleet, and freezing rain are likely on the periphery of the advancing Arctic air mass from the interior South into the Northeast. Stay tuned for further details as the forecast may change. Meanwhile, on Saturday, a plume of moisture will stream into parts of the Pacific Northwest and California, creating heavy rain. Therefore, the WPC has issued a Slight Risk of excessive rainfall over parts of southwestern Oregon and Northern California from Saturday into Sunday morning. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, small streams, narrow canyons/gullies, and burn scars the most vulnerable. Ziegenfelder Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php