Vehicles drive on snow and sleet-covered roads Monday, in Spring, Texas. Texas Gov. Greg Abbott issued a disaster declaration in all of the state's 254 counties.
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Vehicles drive on snow and sleet-covered roads Monday, in Spring, Texas. Texas Gov. Greg Abbott issued a disaster declaration in all of the state's 254 counties. / AP

A powerful winter storm is unloading snow, ice and below-freezing temperatures across the South Central U.S., setting record lows in multiple states and leaving millions of residents without power.

More than 150 million Americans remain under various winter weather advisories as the storm spreads heavy snow and significant ice accumulations from the Southern Plains and Ohio Valley to the Northeast, according to the National Weather Service, which called the area of hazardous weather "unprecedented and expansive."

"This impressive onslaught of wicked wintry weather across much of the Lower 48 is due to the combination of strong Arctic high pressure supplying sub-freezing temperatures and an active storm track escorting waves of precipitation from coast-to-coast," it explained.

The NWS said that "teeth-chattering" cold temperatures will likely continue between the Rockies and Appalachians through Tuesday, with lows in the -20s and -10s for the Northern and Central Plains and Upper/Middle Mississippi Valley.

It predicts that temperature anomalies will be 25 to 45 degrees below normal for much of the Central and Southern Plains on Monday and Tuesday, with wind chill warnings and advisories stretching as far south as the Southern Plains and as far east as the Ohio Valley.

"Hundreds of daily low maximum and minimum temperatures have been/will be broken during this prolonged 'polar plunge,' with some February and even all-time low temperature records in jeopardy," the NWS said.

The record low temperatures attributed to the current "cold snap" may rival those of historic cold periods in Feb. 1899 and 1905, according to the NWS Weather Prediction Center.

It said early Monday that record lows had already been established in parts of Minnesota, Nebraska, Iowa, South Dakota, Kansas, Wisconsin, Colorado, Missouri, Texas and Oklahoma, with temperatures likely to drop even more on Tuesday morning.

For instance, Kansas City, Mo., on Monday reported -32° F wind chill, its lowest recorded since 1989, while Sioux Falls, S.D., announced a record low temperature of -26° F. Cities in Texas including Corpus Christi, Dallas, San Antonio and Austin also saw historic record lows.

The weather conditions have prompted emergency declarations in several states, including Alabama, Oregon, Oklahoma, Kansas, Kentucky and Mississippi. Texas Gov. Greg Abbott issued a disaster declaration in all of the state's 254 counties, and also requested a federal emergency declaration, which President Biden approved on Sunday.

The extreme weather has also meant widespread power outages in many states, according to online tracker poweroutage.us, which reports that thousands of customers are without electricity in Oregon, Virginia, Louisiana, Arkansas, Mississippi, Kentucky, West Virginia and North Carolina.

And in hard-hit Texas, some 2.7 million customers are without power during a rare snowstorm after wintery conditions prompted statewide rolling blackouts.

ERCOT, the agency that oversees the state's electric grid, initiated rolling power outages shortly after midnight in response to peak demand, after previously calling on consumers and businesses to conserve their energy use as much as possible through Tuesday.

The agency said in a press release that the weather conditions had caused many generating units to "trip offline and become unavailable." It added that rotating outages would likely last throughout the morning and could be reinstated until the end of the weather emergency.

"Every grid operator and every electric company is fighting to restore power right now," said Bill Magness, ERCOT president and CEO.

In Austin, the city's community-owned electric utility tweeted on Monday morning that it had "shed load" on all available non-critical circuits, affecting its ability to rotate outages among customers. It said the electric load must be reduced in order to restore service across the ERCOT grid, and asked customers still with power to reduce their energy use.

Around that same time, Houston Mayor Sylvester Turner, himself impacted by the outage, said that the electricity grid was continuing to lose generation and that those who had lost power could remain without it "throughout the day."

"These are not rolling blackouts," he tweeted later in the morning. "We are dealing with systemwide power outages across the state."

Those without power are encouraged to check on their elderly neighbors and heed several safety tips, including using flashlights instead of candles, keeping portable generators outdoors and conserving heat by closing off unused rooms, placing towels or blankets underneath doors and covering windows.

Officials in states including Texas and Louisiana are also asking residents to stay off the roads amidst the dangerous driving conditions. Several COVID-19 testing and vaccination sites in those states are also closed due to the weather.

Thousands of flights within, into and out of the U.S. have also been cancelled and delayed, according to Flight Aware.

NWS forecasters predict that areas in the Southern Plains will stop seeing snow and wintry mix late Monday morning, but "treacherous" travel conditions will persist as frigid temperatures will limit the amount of melting.

Meanwhile, heavy snow and freezing rain are expected to move northeastward, with 6 to 12 inches of snow forecast from the Ohio Valley and eastern Great Lakes to northern New England. The NWS says freezing rain may cause a "plethora of problems" from east Texas to southern New England, with significant ice amounts of a quarter to half an inch likely in some areas.

A band of sleet and freezing rain of up to .25 of an inch is forecast to stretch from the western Gulf Coast through the Appalachians and into southern New England, and the agency warns that travel disruptions and power outages are likely to continue.

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