NASHVILLE — A coast-to-coast winter storm swept from Oregon and Washington to the Southeast on Sunday, part of a frigid weather pattern that created record low temperatures in Minnesota and a 100-vehicle traffic pileup in Texas and that is now producing dangerous conditions across much of the country because of heavy snowfall, perilous ice and dangerously low temperatures.
The National Weather Service said early Monday that at least 150 million Americans were under ice or winter weather advisories. Hundreds of thousands of people were without power. Trucks slid off highways and cars piled up on ice-coated roads. As the storm continued to intensify, officials urged residents to brace themselves.
“The time to prepare for this storm was yesterday,” the National Weather Service in Texas said in an ominous warning issued on Sunday.
By Sunday, the storm’s reach had already spanned the country. Just over 11 inches of snow fell in Seattle, and a record low temperature — minus 50 degrees Fahrenheit — was set in one part of Minnesota. As the storm pushed into Texas, it was expected to deliver the kind of sustained cold and icy conditions rarely seen in places where winter tends to come as more of a glancing blow.
“This will be probably more snow over a larger swath of land to a higher degree than ever before in Texas history,” Gov. Greg Abbott of Texas said at a news conference. On Friday, he issued a disaster declaration for all 254 counties.
Elsewhere, about 300,000 customers in Oregon and 150,000 in Virginia were also without electricity.
Across the storm’s path, officials told people to run any last errands and make final preparations by Sunday morning. In Nashville, forecasters told residents to avoid the roads if possible, and to “drive this morning the way you did when you drove your newborn home from the hospital.”
The Texas Department of Transportation warned drivers to prepare for “a marathon of historically cold air” over the next few days that could make driving dangerous.
The dangers quickly became evident: West of Odessa, Texas, as many as 25 vehicles, including some eighteen-wheelers, were involved in crashes. In Oklahoma, a pileup northeast of Oklahoma City led to several semi trucks catching on fire, the authorities said. A livestream video captured footage of overturned trucks with smoke billowing from them.
“Everybody in this state should have several collective goals over the next few days, one of which should be that we will not replicate what happened in Fort Worth,” Mr. Abbott told reporters, referring to the pileup on Thursday on Interstate 35 involving more than 100 vehicles that led to six deaths and dozens of injuries.
The conditions stemmed from a strong high pressure system that came from the Arctic Circle, bringing in some of the lowest temperatures that parts of the country have experienced in years, said Michael J. Ventrice, a meteorological scientist with IBM.
That allowed for energy to bring a “a very impactful winter storm” from Texas up through the Gulf States from Louisiana all the way up to the Northeast, he said.
After bringing heavy snow across the mountains and lowlands of Washington and Oregon, with significant icing in northwest Oregon on Saturday, the storm was expected to deepen in the Southern Plains, the Weather Service said.
It was expected to shift into the Mississippi, Tennessee and Ohio Valleys and upward into the Northeast through Tuesday. The temperatures in the middle of the country were expected to approach record lows. In Oklahoma City, the temperature on Tuesday is forecast to be minus 9 degrees; the record low of minus 17 degrees was set in 1899.
Temperatures in parts of Oklahoma were 40 degrees lower than usual for this time of year, the National Weather Service said. The duration of the cold conditions is also unusual: Oklahoma may experience nine consecutive days of temperatures below 20 degrees, the Weather Service said.
Most warnings for the storm should expire by Wednesday, but Mr. Ventrice warned that another winter storm with a similar path appeared to be “right on its heels” and was expected to form on Wednesday.
Winter storms are influenced by many factors, but the planet’s warming appears to be part of that icy blend — even while climate change is making winters milder over all. The air that sits over the Arctic is now sweeping down into the southern United States, as a result of a weakened jet stream, which circulates around the pole and usually holds in the frigid air of the polar vortex.
But there is evidence that planetary warming is weakening the jet stream and allowing the cold air to escape to the south — especially when a blast of additional warming strikes the stratosphere and deforms the vortex. The result can be plunging temperatures, even in places that rarely get nipped by frost.
“This could be one of the most costly natural disasters of the year,” said Judah Cohen, the director of seasonal forecasting at Atmospheric and Environmental Research, a company that provides information to clients about weather and climate-related risk. “Texas, which is known for hurricanes, is not known for snow and cold damage” such as burst water pipes, he said, and “it’s not in spite of climate change, but related to climate change.”
In Texas, Austin was locked down for the worst winter storm in a generation. Tree branches laden with icicles bowed toward the ground. Parked cars were covered by sheets of ice. The city with palm trees and typically mild weather braced for possibly more than five inches of snow, an amount not seen since 1966.
The parking lot at a grocery store in San Antonio was full as shoppers grabbed last-minute items before the market closed four hours early.
For Zoe Waldron, 30, the polar vortex and gray sky made her nostalgic for La Conner, Wash., her hometown. But in San Antonio? “It feels like a once-in-a-lifetime event,” she said.
Ms. Waldron’s boyfriend, Patrick Attwater, 34, drove to the couple’s house in Austin on Saturday to heat it to 65 degrees and to let the faucets drip, insurance against burst pipes as temperatures were forecast to dip as low as single digits on Sunday night, forecasters said. “I’m from Kansas,” he said. “When we look at our family up there, it’s minus 20, so we feel luckier here.”
Parts of the Gulf Coast in Texas, Louisiana and Mississippi are quite familiar with brutal weather: hurricanes, floods, thick summer heat. But single-digit temperatures and ice-slicked roads were something different entirely.
In Mississippi, officials told residents they would probably need to stay off the roads until at least Tuesday. They cautioned that the local authorities there were not as equipped as those in Northern states that regularly encounter such wintry conditions.
“We have some plows on our trucks, but it’s not the kind like you have up North that is really designed to put weight on that plow and dig down and get it off of the roadway,” said Melinda McGrath, the executive director of the Mississippi Department of Transportation. “We do not invest in those because this only occurs like once every five years or so.”
Business owners were looking at forecasts and deciding whether to close. Jeff Good, who owns three restaurants in and around Jackson, Miss., said two of his restaurants remained open Sunday night, but the third, a bakery that opens early, would certainly be closed on Monday. “With the weather tonight at midnight, we just can’t see how we can do a 6 o’clock in the morning opening,” Mr. Good said.
Valentine’s Day celebrations had already been curtailed because of the coronavirus pandemic. Now, plans had to be dialed back even more.
Deidre Head, 50, of Jackson said she and her husband had made “tentative plans” for a picnic brunch, but their favorite restaurants were closing early or not offering curbside pickup. Instead, Ms. Head said the couple “settled for a lovely Valentine’s Day brunch in the parking lot of McDonald’s.”
“You get what you can get,” she said.
But even that was disrupted: Rain and sleet started pouring down, so they gave up and went home.
Rick Rojas reported from Nashville, and Marie Fazio from Jacksonville, Fla. Reporting was contributed by James Dobbins from San Antonio, Sarah Fowler from Ridgeland, Miss., David Montgomery from Austin, Texas, Bryan Pietsch from Denver and John Schwartz from New York.