Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 251 PM EST Sat Jan 13 2024 Valid 00Z Sun Jan 14 2024 - 00Z Tue Jan 16 2024 ...Heavy-lake-effect snow downwind from the Great Lakes and heavy snow from parts of the Great Basin to the Central Rockies... ...There is a Slight Risk of excessive rainfall over parts of the Pacific Northwest to Northern California on Saturday... ...There is a threat of rain/freezing rain over parts of the Southern Plains, Lower Mississippi Valley, and Tennessee Valley on Sunday evening into Monday evening... Cold high pressure over the Plains and a wave of low pressure along a stationary front extending from the Southern High Plains across the Central Rockies northwestward to the Northwest will produce heavy snow over parts of the Great Basin to the Central Rockies on Saturday into Sunday. In contrast, upper-level energy and cold air will produce heavy lake-effect snow downwind from the Great Lakes. On Sunday evening into Monday evening, moisture flowing northward over the Western/Central Gulf Coast will intersect cold air over parts of the Southern Plains, Lower Mississippi Valley, and Tennessee Valley, creating a broad band of rain/freezing rain. The cold air associated with the high pressure will produce dangerously cold wind chills. In detail, sub-zero wind chills will affect much of the U.S. and reach into portions of the South. Wind chills through Monday will fall below negative 30 degrees below zero from the Northern Rockies to northern Kansas and into Iowa. Values will drop as low as negatives 65 degrees below zero from Montana across the western Dakotas. These wind chills will pose a risk of frostbite on exposed skin and hypothermia. Have a cold survival kit if you must travel. In addition, lake-effect snow persists through Monday downwind from the Great Lakes. The arrival of colder air will generate heavy snow downwind of the Great Lakes through midweek. Whiteout conditions in the lake-effect snow bands are expected. An additional 12-24 inches of snow will occur through Monday across portions of western and northern New York State and 12 inches plus over Michigan. Furthermore, snow squalls are possible on Sunday. In detail, snow showers or squalls may develop across portions of the Northeast and the northern Mid-Atlantic. Gusty winds and rapidly reduced visibility will result in dangerous travel if squalls occur. Moreover, hazardous cold weather will persist and re-develop over parts of the Midwest. Parts of the Midwest will again experience near-record, dangerously low temperatures and wind chills, with subfreezing temperatures possible in the Deep South by late next week. Over the Western U.S., snow will develop from the West Coast to the Rockies, with ice (rain/freezing rain) in Oregon. Heavy snow, blowing snow, and valley icing will all contribute to poor to impossible travel from Oregon, Idaho, Nevada, and Utah, including the Portland, Boise, and Salt Lake City metro areas. Significant freezing rain is expected today over western Oregon, with tree and powerline damage possible. Further, there is a high avalanche danger in portions of the Sierra Nevada and Rockies mountains. Heavy snowfall and strong winds have created dangerous avalanche conditions across portions of the Sierra Nevada and the Northern to Central Rockies. Travel in, near, or below avalanche terrain is not recommended. In addition, wintry precipitation will develop over the Mid-South by Late Sunday. Areas of snow, sleet, and freezing rain will likely develop and spread across portions of the Southern Plains, through the ArkLaTex, and into the Tennessee Valley Sunday into Monday. Several inches of snow are possible. Accumulating ice is expected from portions of central Texas through the Lower Mississippi Valley. With arctic air firmly in place, impacts from wintry weather may last for several days, resulting in a prolonged period of hazardous travel. 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 through 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. The threat of excessive rainfall ends on Sunday. Elsewhere, light snow will develop over parts of the Central/Southern Appalachians on Monday into Monday evening. Additionally, showers and thunderstorms will develop over the Florida Peninsula from Sunday into Monday. Ziegenfelder Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php