Over 1,500 flights cancelled as winter weather wreaks havoc on US's busiest airports

A frigid polar vortex is wreaking havoc on air travel at some of the nation's busiest airports, including Chicago and Atlanta.More than 1,000 flights were canceled by 9 a.m. on Tuesday, adding to the hundreds more disrupted on Monday.Many airlines have waived change fees for customers flying through affected airports.Over 1,500 flights were canceled Tuesday morning, more than doubling the total of 1,000 disrupted on Monday, as winter weather from Chicago to Boston and Atlanta wreaks havoc on air travel.At United's Chicago O'Hare hub, where the National Weather Service predicts a high temperature of 5 degrees Fahrenheit on Tuesday with frigid windchill extending well into the negatives, more than 150 flights were canceled by 10:30 a.m., according to FlightAware."We expect to operate on a reduced schedule throughout the week," United spokesperson Robert Einhorn told Business Insider. He said the airline was coping with the storm by adding additional ramp workers at O'Hare so that employees could work shorter shifts in the cold as well as move some equipment indoors and out of the elements.Across town, at Midway, Southwest's largest hub, things were just as bleak, with more than 250 flights canceled as of 10:30 a.m. Tuesday. Those travel headaches will only compound the delays from Monday, when 1,200 flights were cancelled, according to the USA Today.Southwest Airlines said that "customers will see flight reduction due to weather," mostly in Chicago and Milwaukee.An American Airlines spokesperson said the carrier had cancelled more than 1,000 flights Tuesday because of snow in the Midwest. Read more: Delta, United, and American bracing for monster storm and issuing travel vouchers. Here's what to know if you're flying."Wintry precipitation could delay flights today from Boston (BOS) to Atlanta (ATL), as well as in Chicago (MDW, ORD)," The FAA's daily air traffic report said Tuesday morning. "Low clouds are expected this morning in San Francisco (SFO). Super Bowl traffic into the Atlanta area is expected to increase today."Super Bowl flights could be disruptedIn Atlanta, where traffic for the Super Bowl is expected to begin hitting the nation's busiest airport on Tuesday, Delta Air Lines said it had proactively canceled "approximately 170 mainline and Delta Connection flights" because of snow and icy conditions.In total, Hartsfield-Jackson had seen 293 flights cancelled as of 10:30 a.m., according to FlightAware. The National Weather Service's winter weather advisory for rain, snow, and black ice in Atlanta is in effect until 7 p.m Tuesday. There were also scattered delays in New York City, Boston, and Washington, DC, because of wind, rain, and snow.If you're traveling today and need to make changes, many carriers have waived change fees for affected airports. Check with your specific airline here:SouthwestUnitedDeltaAmericanRead Business Insider's full coverage of winter storm Jayden and the related polar vortex here.