NEW YORK: On Thursday, the Northeast of the United States braced for a historic deep freeze, with wind chills predicted to drop as low as -50 degrees Fahrenheit (-46 degrees Celsius) in some areas, while freezing rain in the South caused thousands of people to lose power and turned roads into skating rinks.

The National Weather Service predicted that dangerous wind chills were likely to occur starting early on Friday and continuing through Saturday night in a region spanning from northern Pennsylvania to Maine.

The weather service warned that the wind chills could be "once in a generation cold" and advised people to either stay inside or take precautions against frostbite and hypothermia. The combined impact of wind and cold temperatures on exposed skin is known as the wind chill factor.

The Northeast's highest peak, Mount Washington State Park in New Hampshire, was expected to experience record-breaking wind chills of -110 degrees and wind speeds exceeding 100 miles (160 km) per hour.

"It's definitely wicked cold, you can say that," said Frances Tarasiewicz, a weather observer for the park.

"Today it's a seasonal 5 degrees, but it's coming at us quick," he said of the cold blast headed for the Mount Washington Observatory, where staff members live on the mountain in eight-day shifts.

After weeks of unseasonably warm weather in the majority of the region and a lack of snow, with the exception of patches in western and northern New York State, the arctic blast may feel especially shocking to residents of the Northeast.

Mayor Michelle Wu of Boston declared a cold emergency for the largest city in New England from Friday through Sunday because the region will begin to experience wind chills below zero on Friday. Boston has set up warming centers so that people can escape the chilly weather.

"I urge all Boston residents to take precautions, stay warm and safe, and check on your neighbors during this cold emergency," Wu said in a statement.

The aftermath of a winter storm that brought days of freezing rain, sleet, and ice accumulation and caused widespread power outages and dangerously slick roads across the region was being dealt with in Texas and some areas of the South as the Northeast prepared for the cold blast.

A half-inch (1.3 cm) of ice in some places toppled power lines and trees, leaving more than 450,000 homes and businesses without electricity early on Thursday in Texas, Arkansas, Mississippi, and Tennessee, according to Poweroutage.us.

Authorities in the area also urged drivers to avoid the roads after eight fatalities were reportedly caused by icy roads over the past few days, according to CBS News.

Texans from all over the state posted pictures of cars sliding sideways on slick roads and ice-crusted tree limbs bending under the weight on social media. Rob Quigley, a Twitter user, shared a video of a man skating and playing hockey on a glass sidewalk in a Dallas suburb.

The freezing temperatures and ice storms have arrived as Punxsutawney Phil, the famous groundhog predicted. On Thursday, Groundhog Day, Phil saw his shadow, predicting six more weeks of chilly weather across North America.