Subfreezing temperatures across much of the U.S. left millions of Americans facing potentially dangerous cold Sunday as Arctic storms threatened near-blizzard conditions in the northeast and several inches of snow in portions of the South.

The National Weather Service warned that windy, subfreezing conditions in Montana and the Dakotas could push wind chills as low as minus 70 degrees Fahrenheit (minus 56 degrees Celsius).

An estimated 95 million people were under weather warnings or advisories for wind chills below zero F (minus 17 C), according to the weather service. Forecasters said the severe cold push as far south as northern Texas.

Officials warned people to say off the roads in Buffalo, New York, where snowfall of 1 to 2 feet (0.3 to 0.6 meters) was forecast. The severe storm forced the postponement of the Buffalo Bills-Pittsburgh Steelers NFL playoff game from Sunday to Monday. Wind gusts as high as 50 mph (80 kph) were also possible, said Zack Taylor, a National Weather Service meteorologist in College Park, Maryland.

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“They’re expected to see both the intense snowfall, but also the extreme wind,” Taylor said. “That’s why they’re expecting to see near-blizzard conditions at times.”

Airports across the country were impacted. More than half of flights into and out of Buffalo Niagara International Airport were canceled. Scores of flights were also canceled or delayed at Chicago O’Hare International Airport, Denver International Airport and Seattle-Tacoma International Airport.

Another Arctic storm that’s dumped heavy snowfall in the Rockies was forecast to push further south, potentially bringing 4 inches to 6 inches (0.10 to 0.15 meters) of snow to portions of Arkansas, northern Mississippi and west Tennessee.

Arkansas Gov. Sarah Huckabee Sanders declared a state of emergency ahead of the severe weather to give utility trucks and trucks hauling essential supplies greater flexibility to respond.

More than 150,000 homes and businesses in Oregon were without electricity Sunday following heavy snow and ice storms, according to poweroutage.us. Widespread outages affecting tens of thousands were also reported in Michigan and Wisconsin.

The harsh weather in Oregon played a role in three deaths.

In Portland, medical examiners were investigating a hypothermia death as freezing rain and heavy snow fell in a city more accustomed to mild winter rains, and hundreds of people took shelter overnight at warming centers.

Portland Fire and Rescue also reported the death of a woman in her early 30s on Saturday afternoon. An RV caught fire when a small group of people used an open flame stove to keep warm inside and a tree fell on the vehicle, causing the fire to spread. Three other people escaped, including one with minor injuries, but the woman was trapped inside, the fire department said.

Authorities in Lake Oswego, Oregon, said a large tree fell on a home during high winds Saturday, killing an older man on the second floor.

Weather-related deaths already were reported earlier in the week in California, Idaho, Illinois and Wisconsin.