More than 4,600 flights have been canceled nationwide

The winter storm sweeping across much of the United States led to thousands of flight cancellations and delays on Thursday, with many more likely throughout the day. As of early afternoon Eastern time, 4,762 flights scheduled to arrive at or depart from US airports on Thursday had been canceled, and an additional 934 were delayed, according to FlightAware, a tracking website. One of the hardest-hit cities was Dallas, which had about 800 canceled departures and about 750 canceled arrivals. At Dallas-Fort Worth International Airport, 65 percent of departing flights and 60 percent of arriving flights were canceled, and at Dallas Love Field Airport, 84 percent of departures and 78 percent of arrivals were canceled. By a little after noon, Dallas-Fort Worth had reopened one runway but warned, “Due to ongoing weather conditions, we anticipate intermediate stoppages throughout the day to treat for snow and ice.” A majority of flights were canceled at each of the three largest airports serving Ohio — Cleveland Hopkins International Airport, John Glenn Columbus International Airport and Cincinnati/Northern Kentucky International Airport — as well as at airports in St. Louis and in Austin, Texas. On an average day, the FAA handles 45,000 flights, meaning the cancellations and delays on Thursday are affecting more than 10% of air traffic in the United States. That is a remarkably high number: While there is much seasonal variation, daily cancellation totals tend to be less than 2% on average.<br/>