Winter storm disrupts travel in the United States, forcing a large number of flights to be canceled.

A powerful winter storm hit most of the United States, bringing freezing rain and heavy snow, forcing airlines to cancel and delay thousands of flights on Monday. Data from aviation analysis company Cirium shows that by late afternoon, nearly 19% of scheduled flights were cancelled. Another set of data from FlightAware shows that as of late evening, around 5,220 US flights were cancelled, with over 6,500 flights delayed. According to Cirium, 11,000 flights were cancelled on Sunday, the highest daily total since the flu pandemic. A major winter storm dumped a foot of snow from New Mexico to New England, paralyzing much of the eastern United States and causing at least 18 deaths. Extreme cold weather is expected to persist in some areas for a week. Among the airlines, American Airlines had the highest proportion of flights cancelled on Monday, with nearly 1,180 flights cancelled and roughly 1,130 flights delayed, followed by Republic Airways, JetBlue, and Delta Airlines. The Federal Aviation Administration said in a statement that major hubs like Boston and New York were experiencing snowfall, freezing rain, and low visibility weather. Cirium reported that Boston's Logan International Airport had the highest flight cancellation rate on Monday, reaching 71%.