By Nick Carey and Kim Palmer
CHICAGO/CLEVELAND, Ohio (Reuters) - A blast of Arctic air gripped the vast middle of the United States on Monday, bringing the coldest temperatures felt in two decades, causing at least four deaths, forcing businesses and schools to close and canceling thousands of flights.
Shelters for the homeless were overflowing and the weather threatened to briefly curtail some oil production in the severe cold described by some meteorologists as the "polar vortex" and dubbed by media as the "polar pig."
Temperatures were 20 to 40 degrees F (11-22 degrees C) below average in parts of Montana, North and South Dakota, Minnesota, Iowa, Wisconsin, Michigan and Nebraska, according to the National Weather Service.
More than half the flights at Chicago's O'Hare International Airport were closed as fuel supplies froze, leaving crews unable to fill aircraft tanks. The afternoon temperature in Chicago was minus 12 Degrees Fahrenheit (minus 24 degrees C), making it colder than in areas of Antarctica, parts of which hovered around 32 F (0 C) during the southern hemisphere summer.
The Arctic air was moving toward the east coast where temperatures were expected to fall throughout Monday as low as 0 degrees Fahrenheit (minus 18 degrees Celsius) in some areas on Tuesday. The coldest temperatures in years and gusty winds were expected as far south as Brownsville, Texas and central Florida, the National Weather Service said.
The northeast saw unseasonably mild weather and rain, but authorities warned travelers to expect icy roads and sidewalks on Tuesday.
At least four weather-related deaths were reported. In northwest Missouri, a one-year-old boy died Monday when the vehicle he was riding in crashed into a snow plow on an icy highway, according to the Missouri State Highway Patrol.
In Indianapolis, firefighters found the body of an elderly woman outside her home early on Monday.
"It appeared she had been there for a while," said Captain Michael Pruitt of the Wayne Township Fire Department.
A 58-year-old man died on Sunday in northeastern Oklahoma after he lost control of his car on icy roads, the Oklahoma Highway Patrol said. In Chicago, a 48-year-old man died of a heart attack while shoveling snow on Sunday night.
In oil fields from Texas to North Dakota and Canada, the severe cold threatened to disrupt traffic, strand wells and interrupt drilling and fracking operations.
It also disrupted grain and livestock shipments throughout the farm belt, curbed meat production at several packing plants and threatened to damage the dormant wheat crop.
LIFE-THREATENING WIND CHILLS
In Cleveland, Ohio, where the temperature was minus 3 degrees F (minus 19 degrees C) and was forecast to drop to minus 6 degrees F (minus 21 degrees C) overnight, homeless shelters were operating at full capacity. Shelter operators had begun to open overflow facilities to accommodate more than 2,000 people who had come seeking warmth.
"There are also going to be people that won't go into the shelters," said Brian Davis, an organizer with Northeast Ohio Coalition for the Homeless. Frostbite can set in within minutes in such low temperatures, according to experts.
The National Weather Service issued warnings for life-threatening wind chills in western and central North Dakota, with temperatures as low as minus 60 F (minus 51 C).
The U.S. cold snap mirrored or outdid freezing weather in parts of the world as Almaty, Kazakhstan where it was minus 8 degrees F (minus 22 C), Mongolia, where temperatures reached minus 10 degrees F (minus 23 C) and Irkutsk, in Siberia, where it was minus 27 degrees F (minus 33 C).
Some 4,392 flights were canceled and 3,577 delayed, according to FlightAware.com, which tracks airline activity.
Many airlines could not allow their ground crews to remain outdoors for more than 15 minutes at a time. There were hundreds of cancellations by airlines including United, Southwest, and American.
"The fuel and glycol supplies are frozen at (Chicago O'Hare) and other airports in the Midwest and Northeast," said Andrea Huguely, a spokeswoman for American Airlines Group. "We are unable to pump fuel and or de-ice."
After five days of scrambling to catch up from storm delays, JetBlue said it would halt operations at three airports in the New York area and Boston Logan International Airport from 5 p.m. EST (2200 GMT) Monday until 10 a.m. EST (1500 GMT) on Tuesday to give crews time to rest.
The bitter cold combined with blowing snow was complicating rail traffic as well. Union Pacific, one of the largest railroads and a chief mover of grains, chemicals, coal and automotive parts, warned customers on Monday that the weather was causing delays up to 48 hours across Illinois, Iowa, Minnesota, Missouri and Wisconsin.
Following last week's storm that dumped up to two feet of snow on parts of New England, some shoppers opted for the comforts of home rather than venturing out to shop.
Many people did not have the luxury of staying home.
In the western Chicago suburb of Geneva, Beth Anderson, 38, was shoveling the remains of Sunday's snow from her driveway before sunrise on Monday while warming up her pickup truck for the short drive to her job at a mall.
"I just wish I could get the day off too but it would take more than a bit of weather to close down the mall where I work," she said.
(Additional reporting by Colleen Jenkins in Winston-Salem, North Carolina, Nivedita Bhattacharjee in Chicago, Kay Henderson in Des Moines, Heide Brandes in Oklahoma, Carey Gillam in Kansas City, Jana J. Pruet in Dallas, Karen Jacobs in Atlanta and Phil Wahba and Marina Lopes in New York; Writing by Ellen Wulfhorst and Scott Malone; Editing by Grant McCool)