[00:00.10]From VOA Learning English, this is In the News.
[00:09.31]A weather system known as a polar vortex brought dangerously cold weather to large parts of the United States this week.
[00:20.26]A polar vortex is a cold, thick low pressure system.
[00:25.86]The air turns counter-clockwise when on the move.
[00:30.78]The polar vortex started up in Canada.
[00:34.69]After crossing the border, it moved deep into the southeastern United States.
[00:41.13]The polar vortex brought the coldest temperatures in more than 20 years to many areas.
[00:49.85]Anise Jenkins lives in Washington, DC.
[00:54.36]"I have a coat on.
[00:55.97]I have three sweaters.
[00:57.08]I have two blouses.
[00:58.20]I have a thermal on and I don't feel like I have anything on."
[01:02.08]Another woman, named Amanda, lives nearby in Maryland.
[01:06.85]"It's DC.
[01:07.94]It's not supposed to be this cold."
[01:10.09]The weather was also a shock to visitors from overseas.
[01:14.92]Deepak from India was visiting his sister in New York.
[01:19.90]"Tears just come out from my eyes and my head inside like a freezy.
[01:25.05]Oh, my God.
[01:26.82]Oh, my God."
[01:28.85]The extreme weather started with a low-pressure system near the North Pole.
[01:35.31]The Arctic air was pushed as far south as Alabama on wind currents known as the jet stream.
[01:43.59]The bitter cold covered much of the central United States, forcing schools, government offices and businesses to close.
[01:53.84]Camden Walker is a reporter for the Washington Post.
[01:58.84]He is part of the newspaper's Capital Weather Gang, which limits its reporting to the weather.
[02:06.24]"When the jet stream came south, the floodgates opened from the north and we had a direct flow from the Arctic."
[02:12.37]But the polar vortex did not have the same effect everywhere.
[02:16.49]"Interestingly enough, it is warmer in Alaska and also somewhat warmer over Greenland
[02:21.80]because when you deplete the North Pole and the Arctic region of its cold air, when it's forced southward, it can't all stay there.
[02:30.95]Basically it's a bubble that is draining toward us.
[02:33.38]It is rushing towards us in the United States."
[02:35.64]Camden Walker says the weather system moved away quickly from places like Washington.
[02:42.00]But the cold air and high winds were staying longer in the middle of the country.
[02:48.67]At least 20 deaths were blamed on the cold weather nationwide.
[02:54.81]Health experts said people should go outside buildings for only 10 to 20 minutes at a time.
[03:03.49]They warned that being outside in such cold can cause frostbite.
[03:09.88]This condition may cause exposed parts of the body to freeze.
[03:15.46]Temperatures of minus 10 degrees Celsius or lower were reported in Washington, New York, Boston and Philadelphia.
[03:25.97]In fact, temperatures in all or parts of the 50 states were below freezing at some point on Tuesday.
[03:35.71]Even in Hawaii, it was minus six degrees at the top of the state's highest mountain.
[03:43.79]The effect of the polar vortex was extensive.
[03:47.52]Airline companies cancelled more than 11,000 flights over a four day period.
[03:54.95]The cold weather also interfered with train service.
[03:59.57]In the south, the Tennessee Valley Authority said it set a single day record for electricity as homeowners struggled to stay warm.
[04:11.94]The TVA provides power to seven states.
[04:16.59]And it was not just North America that experienced extreme cold.
[04:22.06]Over in the Pacific Ocean, a Russian research ship was stuck in ice for over a week.
[04:30.13]The Shokalskiy left New Zealand on November 28.
[04:36.59]The ship was carrying 52 passengers when it became stuck.
[04:40.67]They were rescued January 2, when a helicopter flew them to an Australian icebreaker.
[04:48.41]And that's In The News from VOA Learning English.
[04:54.06]I'm Steve Ember.