CHICAGO -- In Illinois, temperatures were expected rise by 80 degrees within days. In Michigan, melting snow and rain and a 17-mile ice jam on the Muskegon River threatened to flood surrounding areas. And across the Midwest, the warmer forecast was sure to mean more broken roads and burst water mains.
The polar vortex that brought many cities to a standstill was expected to come to a swift end with a rapid thaw that experts say could be unprecedented. But the sudden swing from long johns to short sleeves could create problems of its own.
"I don't think there's ever been a case where we've seen [such a big] shift in temperatures," in the winter, said Jeff Masters, meteorology director of the Weather Underground firm. "Past record-cold waves have not dissipated this quickly. ... Here we are, going right into spring-like temperatures."
On Thursday, the system marched east, spreading arctic conditions over an area spanning from Buffalo to Brooklyn in New York. In western New York, a storm that dumped up to 20 inches of snow gave way to subzero temperatures and face-stinging wind chills.
In New York City, about 200 firefighters battling a blaze in a commercial building took turns getting warm on buses. The number of deaths that can be blamed on the cold climbed to at least 15.
For the nation's midsection, relief is as close as the weekend.
Rockford, Ill., was at a record-breaking minus 31 Thursday morning but should be around 50 by Monday. Other previously frozen areas could see temperatures 55 degrees or higher.
The warm-up will offer a respite from the bone-chilling cold that led to canceled schools, closed businesses and halted trains. But potholes will appear on roads and bridges weakened by the freeze-thaw cycle. The same cycle can crack water mains and homeowners' pipes. Scores of vehicles will be left with flat tires and bent rims.
Joe Buck, who manages Schmit Towing in Minneapolis and spent about 20 hours a day outdoors this week responding to stranded vehicle calls, said he's already taking calls for Monday to deal with a backlog of hundreds of stalled vehicles.
"Sunday is going to be 39 degrees above zero," said Buck, who has had 18 trucks running around the clock.
In Detroit, where some water mains are almost 150 years old, city workers were dealing with dozens of breaks, said Palencia Mobley, deputy director of the Detroit Water and Sewerage Department.
"We'll have all hands on deck. Hopefully, we'll be able to address as many of the issues as possible over the next week," Mobley said.
The thawing of the pipes can sometimes inflict greater damage than the initial freeze. Bursts can occur when ice inside starts to melt and water rushes through the pipe, or when water in the pipe is pushed to a closed faucet by expanding ice.
Elsewhere, a bridge in the western Michigan community of Newaygo, 40 miles north of Grand Rapids, was closed as the ice-jammed Muskegon River rose above flood stage. Officials in Buffalo, N.Y., watched for flooding on the Upper Niagara River because of ice.
In other signs that the worst of the deep freeze was ending, Xcel Energy on Thursday lifted a request to its Minnesota natural gas customers to temporarily lower their thermostats to ease concerns about conserving gas.
Chicago's temperature dropped to a low of around minus 21 degrees Thursday, slightly above the city's lowest-ever reading of minus 27 degrees in January 1985. Milwaukee's low was minus 25 degrees, and Minneapolis recorded minus 24 degrees. Wind chills were lower still.
In Michigan, efforts to conserve heat during the extreme cold reduced usage by 10 percent after a fire at a major natural gas facility, officials said. Consumers Energy, the state's largest supplier of natural gas, asked its 1.7 million customers and others to continue to set their thermostats at 65 degrees or lower until today.
"In our 130 years, we've never experienced this kind of demand or these kinds of temperatures," CEO Patti Poppe said.
Masters, from Weather Underground, said the polar vortex was "rotating up into Canada" and not expected to return in the next couple of weeks. If it does return in late February, "it won't be as intense."
Information for this article was contributed by Martin Crutsinger, David Eggert, Amy Forliti, Corey Williams, Ed White, Blake Nicholson, Caryn Rousseau and Michael Tarm of The Associated Press.
Ice covers their fishing boat, Buzzards Bay, as Mike Calen (left) and Steve Goyette tie it off after returning to port Thursday in New Bedford, Mass. A dangerous arctic system that has walloped parts of the nation for days began moving east Thursday. For the nation’s midsection, temperature swings are forecast to move from subzero readings to the mid-50s or higher.
A Section on 02/01/2019
Print Headline: States brace for thaw after cold