After Freeze Grips Much of U.S., a Warm Respite Beckons

In Dallas, where temperatures dropped as low as 10 degrees last week, highs were forecast to reach the 60s on Wednesday. In New York City, where the low dropped to 17 on Wednesday, unseasonably high temperatures in the 50s were expected by Thursday. And in St. Louis, which was covered in ice on Monday, a high of 50 was expected on Wednesday.

Forget climate change. That’s climate whiplash.

It may be disorienting, but for many it is not unwelcome. Sitting in a frigid Bryant Park in New York City on Monday, Adia Rafio, 26, of Queens said she was considering making outdoor plans later this week.

“I’m definitely going to take advantage,” she said as workers shoveled snow and ice nearby. “Winter is really wintering right now.”

After a mass of Arctic air gripped much of the country last week, a large swath of the United States was expecting significantly warmer weather in the next few days, according to forecasters.

Some cities could see temperature swings of more than 50 degrees. In Little Rock, Ark., which dropped to 1 degree on Wednesday, temperatures were expected to rise into to the 50s by Tuesday and into the 60s by Thursday, according to the National Weather Service. Cities in the Northeast, including New York and Washington, were expected to have highs about 10 to 15 degrees above normal, according to the Weather Service.

With that warmer weather, many outdoor spaces were preparing for more visitors, who might be tired of huddling indoors to stay out of the cold. Jim Breheny, director of the Bronx Zoo, said that more visitors were expected later this week when temperatures rise.

“With the temperature about to turn from frigid to a little warmer, it’s likely more New Yorkers may have cabin fever and more will want to come to our parks,” he said.

The source of last week’s frigid weather was a large mass of Arctic air that stretched from the Northeast into the South, said Michael Musher, a meteorologist with the National Weather Service.

“It was the first true Arctic air mass of the winter season,” he said.

The brutally cold weather was blamed for the deaths of at least 72 people who died from weather-related causes, such as hypothermia. The cold spell also broke at least 15 low-temperature records across the country, according to the Weather Service.

That Arctic air mass has since moved offshore, ushering in warmer weather for much of the country that could stick around for about two weeks for “almost three-quarters of the country,” Mr. Musher said.

“There’s not a whole lot of cold air,” he said. “There’s quite a warm anomaly.”

Jackie Wallace, a spokeswoman for the Houston Zoo, said the 55-acre park was expecting more visitors this week as the weather improves. After dropping to 18 degrees on Jan. 16, temperatures in Houston rose into the 60s on Monday, albeit with a rain in the area, according to the Weather Service.

“Once we get past the heavy rainfall currently coming through Houston, we are expecting to see an uptick in visitation,” Ms. Wallace said.

Bryant Park officials said they were also expecting more visitors as the weather warms. On days when the weather is milder, as many as 1,900 people are in the park at peak hours. On Jan. 16, when temperatures in New York did not rise above freezing, fewer than 100 people were in the park at 1 p.m., park officials said.

While the temperature upswing was welcome news for many who had grown weary of the cold weather, Greg Carbin, chief of forecast operations at the Weather Prediction Center, said such a change in weather can cause problems, such as potholes and ice jam flooding, when ice breaks loose, then gets trapped and piles up, creating a temporary dam.

In some regions, though, the respite from the frigid weather could be brief. After forecast highs in the 50s later this week, temperatures in New York City could fall back into the 30s by Sunday, according to the Weather Service.

Still, Mr. Musher said that the colder weather was expected to be a brief “glancing shot of Arctic air” in the Northeast.

“The overall trend is a mild couple of weeks coming up for most of the U.S.,” he said.

But more frigid cold spells could arrive before winter’s end, forecasters said.

“It’s not over yet,” Mr. Carbin said, adding that cold air the Polar regions was “far from used up.”