Many northern cities could stay below freezing through the end of the month.
The intense cold that's plagued much of the central, eastern and southern USA recently shows no signs of relenting, as wave after wave of cold air is forecast to continue: "We're going to be stuck in this pattern through the end of January," said AccuWeather meteorologist Alex Sosnowski.
How rare is this type of cold outbreak? "It's a once-in-a-decade kind of event," he said, citing the persistence of the cold that's most notable.
Parts of all 50 states -- even Hawaii -- will see below-freezing temperatures early Friday morning, while below-zero wind-chill temperatures will be common across the North.
Even the normally balmy Gulf Coast isn't escaping the chill, as a blast of frigid air overnight tonight and into Friday will make it as far south as the coasts of Texas and Louisiana.
Snow, sleet and freezing rain are all possible in both Houston and New Orleans early Friday.
It's the first time in more than three years that Houston has been under a winter storm warning. Highways, bridges and overpasses will be extremely dangerous, the National Weather Service warns, advising residents to "please avoid travel at all costs" in an online bulletin.
Freakishly, many parts of Alaska are seeing warmer weather than the Lower 48; temperatures Thursday morning were actually warmer in Fairbanks than in parts of central Florida.
Into next week, the center of the now well-known "polar vortex" will hover just north of the U.S. border, according to Sosnowski. The vortex will continue to hurl chunks of cold air roaring into the Midwest and much of the East through the end of the week.
Temperatures could remain below freezing in Minneapolis, Chicago, Milwaukee, Detroit and Cleveland through the end of the month, Sosnowski reports, with highs most days only in the teens.
In Boston, Pittsburgh, Philadelphia, New York City and Indianapolis, temperatures may only get above freezing on one or two days through Jan. 31.
Several small winter storms, known as Alberta Clippers, will ride along with the cold blasts over the next few days, spreading snow and howling winds from the Upper Midwest to the Northeast. The first one will bring some snow showers and squalls Friday night and into Saturday, while yet another storm will pinwheel through on Sunday and into Monday.
The cold pattern could ease slightly by early February, with the heart of the frigid weather shifting a bit to the west, Sosnowski said.