Polar vortex brings ‘dangerous cold’ to US
Much of North America was gripped by the coldest weather in decades as extreme conditions, caused by a polar vortex – a pattern of winds that traps cold air – spread east and south on Tuesday. The US National Weather Service warned of "dangerously cold Arctic air" overtaking the eastern two-thirds of the country, with temperatures below freezing "in most places from the central plains to the east coast and as far south as the gulf coast." Travellers have been stranded and the American Red Cross said 117m people were threatened by dangerous wind-chills as the effects of the freeze extended from Montana to southern Florida. At least six weather-related deaths were reported. The cold weather was caused by part of the polar vortex, a "persistent large-scale upper-level cyclone", peeling away from where it usually sits above the North Pole and being sent south by the jet stream, the US weather service said. The cold broke records, with temperatures dropping in New York’s Central Park on Tuesday to 4F (minus 15C) and in Chicago on Monday to minus 16F. Atlanta, Georgia, recorded its coldest day in 44 years on Tuesday with a temperature of 6F. Temperatures were forecast to be 25-35F below average in the mid-Atlantic and southeast. Travel was snarled, with roads closed and more than 2,000 US flights cancelled on Tuesday, according to flight tracker FlightAware, following more than 4,100 cancellations on Monday. Toronto’s airport was closed to arrivals as equipment froze. JetBlue Airways was slowly resuming operations at four airports in New York and Boston where service was suspended on Monday to allow the airline to get planes and crews into place after disruptions from last week’s snowstorm. JetBlue cancelled nearly half its scheduled flights on Monday, the most of any US carrier. The airline said it was adding flights on Tuesday to help travellers stranded as far away as the Caribbean and South America. Amtrak, the national rail operator, stopped trains in and out of Chicago, ran a reduced service from New York to Boston and cancelled trips on other routes. More than 500 Chicago-bound passengers spent Monday night on three trains in Illinois that were forced to a standstill by snow and ice. Energy demand soared across many parts of the country. Some power plants were also shut down by the freeze, leading PJM Interconnection, which runs the power grid in 13 states and the District of Columbia, to ask customers to conserve electricity to avoid outages. In Indiana, 15,000 customers were without power and officials said it could take days to restore services to some areas. Gasoline futures saw their first rise in seven days after refineries from Newfoundland to Louisiana shut because of the cold. Natural gas futures in New York fell, however, on forecasts for a return to milder weather this week. On Monday, the price for natural gas for next-day delivery on the Transco pipeline into New York had surged to a record $90 per million British thermal units, 20 times more than benchmark futures prices, according to the ICE Futures US exchange. The coldest "real air" temperature on Tuesday morning was minus 35F in Embarrass, Minnesota. That was colder than the minus 32F recorded on Mars on January 2 by Nasa’s Curiosity rover. Taking into account the wind-chill factor, temperatures in New York were forecast to reach lows of minus 15F on Tuesday. Andrew Cuomo, the state’s governor, declared a state of emergency in 14 counties, warning of "truly extraordinary" conditions. Snowfall was forecast in southern states, including Oklahoma and Arkansas, on Wednesday. Hard freeze warnings extended from Texas to Florida. Schools from Illinois to New York were closed on Tuesday, and many companies and government offices ordered staff to stay at home as record-low temperatures set in. The chill is expected to ease slightly by Wednesday, returning to January norms by the end of the week.