Multiple winter storms are bringing snow, ice and dangerously cold temperatures to many parts of the country over the long holiday weekend.

More than 100 million Americans were under some sort of winter weather advisory on Saturday, according to the National Weather Service.

In its forecast, the weather service warned of a "myriad of winter weather hazards across the continental U.S." over the coming days, including heavy snowfall throughout the Pacific Northwest and icy weather and slick travel conditions in the mid-Atlantic.

Snow has already blanketed much of Oregon and Washington. Seattle picked up a foot or more.

A similar scenario occurred in Portland, where up to 10 inches of snow covered areas of the city. In addition to the snowfall amounts, three-quarters of an inch of ice accumulation and gusty winds caused widespread power outages across Oregon, according to the Weather Channel.

Utility companies have been working to restore power, but more than 260,000 customers were without power in northwest Oregon as of Saturday afternoon, according to PowerOutage.us.

The winter weather also resulted in treacherous driving conditions as downed trees, power lines and ice forced many road closures across the state, the Oregon Department of Transportation said in a statement on Twitter.

Forecasters predict more snowfall throughout the West, particularly in higher elevations, as the system moves over the Rocky Mountains.

As much as a foot of snow could fall in parts of Oklahoma and the Texas Panhandle through Sunday night, according to the NWS.

Texas Gov. Greg Abbott declared a state of emergency, warning of near-blizzard conditions in the Dallas-Fort Worth area and historic low temperatures. He said he would ask the White House to issue a federal emergency declaration for Texas.

The weather service said temperatures could dip to -30 degrees in some parts of the country, with "life-threatening wind chills" between -30 to -60 degrees in the north-central U.S.

Along the East Coast, heavy rainfalls and potential flash flooding were expected to impact parts of Florida, Georgia and Alabama.

Further north, forecasters warned of an icy wintry mix, with the worst impact to be felt in Virginia.

"Up to a half inch of ice is possible in these areas," the weather service said. "Downed tree limbs and power outages expected."

Like his counterpart in Texas, Virginia Gov. Ralph Northam decided to declare a state of emergency ahead of the anticipated winter weather.

Nearly 300,000 customers have lost power across the state.

The winter weather has also disrupted air travel over this Presidents Day weekend. More than 1,600 flights have been canceled within, to and from the U.S. across Saturday and Sunday, according to flight tracker FlightAware.com.

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