The frigid polar vortex that killed 21 people is on the way out — and temperatures are due to spike by up to 80 degrees

Twitter/National Weather Service Weather Prediction CenterA graphic showing high temperatures forecast for Sunday.
  • The polar vortex that brought deadly cold to the US is coming to an end, and temperatures could rapidly rise by as much as 80 degrees Fahrenheit this weekend.
  • The warmer conditions will be welcomed after record-low temperatures disrupted towns and cities and killed at least 21 people.
  • But the rapid thaw could create some new problems, including flooding, potholes, and burst pipes.
  • Wintry conditions could also return to some parts of the Midwest and Northeast next week, though it likely won’t be as cold as during the polar vortex.

The polar vortex that brought record-low temperatures to the US and killed at least 21 people is coming to an end – and temperatures are expected to spike this weekend.

The polar vortex brought temperatures lower than minus 50 degrees, and forecasters are predicting that some places will become up to 80 degrees higher than their lowest temperatures during the week.

The rebound in temperature could set records of its own. Jeff Masters, meteorology director of the Weather Underground firm, said, “I don’t think there’s ever been a case where we’ve seen [such a big] shift in temperatures,” according to The Associated Press.

“Past record-cold waves have not dissipated this quickly,” he added. “Here we are going right into spring-like temperatures.”

Read more: The polar vortex ravaging the US with extreme cold has killed at least 21 people

Chicago snow frozen polar vortexScott Olson/Getty ImagesIce builds up along the shore of Lake Michigan, Chicago, on Thursday.

Rapidly rising temperatures bring their own problems

The more than 20 million Americans who experienced the life-threateningly low temperatures will likely welcome the milder weather after thousands of flights were canceled, schools were closed, and the US Postal Service suspended operations because of the severe weather.

But the speed at which much of the country is expected to get warmer brings its own problems.

Extreme cold followed by a quick thaw can damage roads, leaving them cracked and filled with potholes.

The heating and cooling of the pavement cause it to expand, contract, and then crack, The Weather Channel warned. Melted water from ice can get into those cracks and freeze overnight, expanding and making the cracks even bigger.

Cars and trucks driving over those cracks can break the road surface further, creating potholes.

New York Manhattan Snow cold polar vortexSpencer Platt/Getty ImagesPeople walk through the snow in lower Manhattan on Wednesday.

Meteorologist Brian Donegan wrote on The Weather Channel: “Since the temperature was so bitterly cold and is now expected to warm up significantly in the days ahead, road surfaces will become stressed due to that quick transition from freeze to thaw. This is why numerous potholes will likely form in the Midwest and Northeast.”

The rapid thaw can also produce “ice jams,” the large chunks of ice created when a frozen river begins to melt. These can get stuck or pile up in rivers, causing water to overflow and flood the surrounding area.

Melting ice water from surrounding areas can flow into rivers and lakes, also causing flooding.

Additionally, pipes can freeze and burst.

Anthony Tornetta, a spokesman for the American Red Cross, told USA Today, “Unfortunately, this polar vortex is gripping a large portion of the country and frozen pipes is an unfortunate reality in some cases.”

Read more: A polar vortex is engulfing the US. Here’s what that really means, and why these events might be getting more common.

Chicago polar vortex snow ice cold weather photographerScott Olson/Getty ImagesPhotographers take pictures of the sunrise as temperatures hover around minus 20 degrees Fahrenheit in Chicago on Thursday.

Some parts of the country may have to embrace the cold again

Some parts of the US may have to brace themselves for the return of winter weather after the warm spell, though it won’t be as cold as the polar vortex.

Donegan, the meteorologist at The Weather Channel, said the “mild pattern is not expected to be prolonged” for some parts of the country.

He warned that “below-average temperatures might return to the Midwest and Northeast next week,” but added, “The good news is that it likely won’t be as harsh as this week’s arctic blast.”

Some branches of the National Weather Service are warning people to prepare for cold weather next week after a warmer weekend.

The weather service in Sioux Falls, South Dakota, warned that an “Arctic chill” may return next week after a “great” weekend.

The weather service in Chicago predicted a significant increase in temperatures next week, with a high of 56 degrees on Monday.

However, it warned of rain and ice over the weekend and into next week.

Business Insider Emails & Alerts

Site highlights each day to your inbox.

Follow Business Insider Australia on Facebook, Twitter, LinkedIn, and Instagram.