Winter weather advisories, including lake effect snow warnings, have been issued by the National Weather Service (NWS) for nine states as a powerful winter storm system sweeps across the northern U.S.
Lake effect snow is a weather phenomenon that occurs when cold, dry air moves over a large, warmer body of water, such as the Great Lakes. This temperature difference causes the air to pick up moisture from the lake’s surface, and as the air moves over the land, it cools and the moisture condenses, forming snow.
Residents in the affected states of Oregon, New York, Washington, Alaska, Idaho, Montana, Vermont, Michigan, and Minnesota are urged to prepare for hazardous travel conditions, localized power outages, downed trees, and significant snowfall accumulations.
New York
A weather advisory is in place until 10 a.m. EST Sunday. Lake effect snow with additional accumulations of 3 to 7 inches is expected in Southern Oneida County. The highest snow amounts are expected to be north of Interstate 90. The lake effect snow will transition to widespread light to moderate snow late Saturday afternoon through Sunday morning as a low-pressure system approaches the area.
Additional snow accumulations of 1 to 3 inches in Northern Cayuga County are expected, mainly near the Lake Ontario shore. Herkimer County, south of Route 28 and north of Interstate 90, is expected to see the highest snowfall amounts.
NWS/National Weather Service
Oregon
Snow is expected above 3,000 ft, with total snow accumulations of 6 to 10 inches and winds gusting as high as 40 mph in North Oregon Cascades. A weather advisory is in place from 4 p.m. Saturday to 4 p.m. PST Sunday.
Snow levels will start high Saturday morning at over 9,000 ft before lowering to around 5,000 ft Saturday afternoon and then down to 3,000 ft Saturday night, where they will remain through Sunday night. The period of heaviest snowfall is expected to occur late Saturday night through Sunday morning.
Total snow accumulations of 5 to 10 inches and winds gusting as high as 40 mph are expected in the Northern Blue Mountains.
Washington
Snow is expected at or above elevations greater than 3,000 ft, with total snow accumulations between 6 to 10 inches and winds gusting as high as 45 mph on the West Slopes, South Central Cascades, and Passes.
The weather advisory runs from 4 p.m. Saturday to 4 p.m. PST Sunday.
Idaho
A winter weather advisory remains in effect from 4 a.m. to 10 p.m. PST Saturday.
Total ice accumulations around one-tenth of an inch and snow accumulations up to 6 inches are expected above 3,500 feet. Localized ice accumulations of a quarter of an inch are possible, especially in Pend Oreille County.
Snow and freezing rain are expected in Lower Treasure Valley Zones, and northern Malheur County including Highways 20 and 26.
Alaska
An inter-weather advisory is in effect from 9 a.m. Sunday to 9 a.m. AKST Tuesday for Yukon Delta Coast, Lower Yukon River, and Lower Yukon and Innoko Valleys.
Mixed precipitation is expected, with total snow accumulations of 2 to 5 inches and ice accumulations of a light glaze. Up to 8 inches of snow is possible in higher terrain and winds gusting as high as 40 mph.
Michigan
Total snow accumulations between 4 and 7 inches are expected in Chippewa and Mackinac Counties, with a weather advisory in place from 5 a.m. early this morning to 5 p.m. EST Saturday afternoon.
The greatest snow accumulations are expected north of Houghton with an advisory in place until 1 p.m. EST Saturday afternoon.
Montana
A winter weather advisory is in effect from noon Sunday until 8 a.m. MST Monday, with several counties affected.
Total snow accumulations between 1 to 4 inches, with 4 to 8 inches in northerly upslope favored areas expected, 6 inches possible over Chief Joseph and Big Hole Pass.
Up to 3 to 7 inches possible over Marias Pass, and higher amounts in the mountains of the Glacier National Park. Winds 40 to 50 mph with gusts up to 85 mph expected at the Continental Divide along the Rocky Mountain Front. Advisories are in place from 11 a.m. this morning to 5 p.m. MST Sunday.
Minnesota
Snow and freezing drizzle are expected, with additional snow accumulations up to one inch and ice accumulations around a light glaze in Central St. Louis County. This includes the Tribal Land of the Bois Forte Band, Lake Vermilion area. Advisories are in place until noon CST Saturday.
NWS advises that a Sunday afternoon through Monday morning snow event is forecast to have lower snow-to-liquid ratios closer to 7 to 10 inches of snowfall to one inch of liquid water equivalent. These lower snowfall ratios could produce a wetter and heavier snow load than the more recent lighter and fluffier snow events.
Total wet snow accumulations between 4 and 9 inches are possible. Local wet snow accumulations of up to 12 inches are possible in eastern Cook County.
Vermont
Total snow accumulations between 3 and 7 inches are expected in St Lawrence and southern Franklin Counties, with an advisory in place from 3 p.m. Saturday afternoon to 1 p.m. EST Sunday.
For more details and advice, those in all affected states are advised to check NWS for current and further updates as the storm continues to unfold.
