Winter weather warnings are in effect in 15 states, with heavy snow up to four feet and high winds expected.

Storm warnings and advisories are in effect in Maryland, Idaho, California, Pennsylvania, West Virginia, New York, Virginia, New Jersey, Nevada, Alaska, Montana, Kentucky, South Carolina, Ohio and Tennessee.

“Strong storm system to bring cold temperatures, high winds and snow to areas east of the Rockies,” the NWS (National Weather Service) said in a briefing.

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The heaviest snow accumulations are forecast in California, where up to four feet of snow and high winds are expected.

About the West Slope Northern Sierra Nevada and Western Plumas
County/Lassen Park Counties, the NWS said: “Heavy snow is expected at elevations above 5,500 feet. Total snow accumulations of 3 to 3 feet and up to 4 feet along higher peaks. Wind gusts up to 50 mph.” A winter storm warning is in place from 4pm Friday to 4pm Tuesday, and travel will be virtually impossible.

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Up to four feet of snow and wind speeds of 50 miles per hour are also expected in Yosemite National Park, outside the valley.

Strong winds look to impact many states this weekend.

Winds of 50 mph are also expected in Grayson County, Virginia, and Avery, Madison, Mitchell and Yancey counties in South Carolina. Winter weather advisories are in effect for these areas.

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Wind gusts up to 40 mph could hit Northwest Randolph, Southeast Fayette and Southeast Nicholas Counties of West Virginia, and Cambria and Somerset Counties in Pennsylvania on Friday.

In all 15 affected states, the NWS said travel could be dangerous as roads could be slippery and heavy snow and wind could topple trees and power lines.

In Maryland, where heavy snow and winds of up to 45 mph are expected, the NWS said “gusting winds are expected that will make travel treacherous and potentially life-threatening. Travel may be very difficult to impossible.”

Conditions will also be treacherous in northeastern Montana, where the NWS warns of “a wintry mix of snow, sleet and freezing rain, changing to all snow Saturday evening.” Snow totals will be between 2 and 5 inches and ice accumulations could reach several hundredths of an inch.

In all areas, those who do travel are advised to have an extra flashlight, food and water in their vehicle in case of an emergency.

When going outside, the NWS also says to be careful with your first few steps on stairs, sidewalks and driveways, as they can be icy and slippery.

Winter conditions across the 15 states are a mix of winter storm warnings and weather advisories. Storm warnings are issued when a significant combination of dangerous winter weather occurs or threatens. This hazardous weather is defined as “5 inches or more of snow/ice in a 12-hour period or 7 inches or more of snow/freeze in a 24-hour period, ice accumulation that could damage power lines, and a life-threatening or damaging combination of snow and /or ice accumulation with wind.”

In conditions where “any amount of freezing rain, or when 5 to 10 cm of snow (alone or in combination with sleet and freezing rain) is expected to cause significant discomfort but not severe enough to warrant a warning”, winter weather advisories may be issued released.