Massive winter storm sweeps across US bringing ice, frigid temps

A massive winter storm on Saturday dumped snow and freezing rain on New Mexico and Texas as it swept across the United States towards the northeast, threatening tens of millions of Americans with blackouts, transportation chaos and bone-chilling cold.

Shoppers stripped supermarket shelves as the National Weather Service (NWS) forecast huge snowfall in some areas and possibly "catastrophic" ice accumulations.

Transportation Secretary Sean Duffy warned that up to 240 million Americans could be affected by the storm. At least 16 states and the US capital Washington have declared states of emergency.

"Take this storm seriously, folks," the NWS said on X, predicting an "astonishingly long swath" of snowfall from New Mexico to Maine.

More than 3,900 flights in and out of the United States were cancelled on Saturday alone, and more than 3,000 others were delayed, according to tracker FlightAware.

In Dallas, which has typically mild temperatures in January, freezing rain pelted the Texas city, and the mercury plummeted to 21F (-6C).

Houston Mayor John Whitmire meanwhile urged residents of the country's fourth most populous city to hunker down by late Saturday: "Be where you need to be for the next 72 hours."

Eric Maple, a 56-year-old homeless man, was waiting Sunday for a warming centre to open in Houston.

"We're not used to what's supposed to be coming," he told AFP.

"It disrupts things in Houston, but our city's strong and we've got good people here, so we all try to pull together."

State officials vowed that the Texas power grid was in better shape than five years ago, when it failed during a deadly winter storm and left millions without power.

Nearly 130,000 US customers were without power as of Saturday afternoon, according to tracking site poweroutage.us, with over 50,000 reported in both Texas and neighbouring Louisiana.

Snow also hit Oklahoma and Arkansas, where some spots already recorded six inches (15 centimetres) on the ground, the NWS said.

After battering the country's southwest and central areas, the storm system was expected to hit the heavily populated mid-Atlantic and northeastern states before a frigid air mass settles in.

"The snow/sleet impacts will linger well into next week with rounds of re-freezing that keeps surfaces icy and dangerous to both drive and walk on for the foreseeable future," the weather service said.

The US federal government pre-emptively announced offices in Washington would be closed on Monday.

"We will continue to monitor and stay in touch with all States in the path of this storm. Stay Safe and Stay Warm!" US President Donald Trump, who was riding out the storm at the White House, said on his Truth Social platform.

Polar vortex

The brutal storm system is the result of a stretched polar vortex, an Arctic region of cold, low-pressure air that normally forms a relatively compact, circular system but sometimes morphs into a more oval shape, sending cold air spilling across North America.

Scientists say the increasing frequency of such disruptions of the polar vortex may be linked to climate change, though the debate is not settled and natural variability plays a role.

But Trump – who scoffs at climate change science and has rolled back green energy policies – questioned how the cold front fit into broader climate shifts.

"WHATEVER HAPPENED TO GLOBAL WARMING???" the Republican leader posted on Truth Social.

The NWS warned that heavy ice could cause "long-duration power outages, extensive tree damage, and extremely dangerous or impassable travel conditions," including in many states less accustomed to intense winter weather.

Five or six minutes

New York Governor Kathy Hochul warned residents to stay inside amid frigid conditions: Five- or six-minutes outside could literally be dangerous for your health."

She stressed precautions like protecting pipes, using heaters safely, and checking on vulnerable neighbours.

Authorities warned of life-threatening cold that could last a week post-storm, especially in the Northern Plains and Upper Midwest, where wind chill lows were forecast to dip to extremes under -50F (-45C).

Such temperatures can cause frostbite within minutes.