Disruptions for air travelers continued Tuesday with more than 1,600 flights across the United States delayed or canceled after powerful storms ripped through the parts of the country, including in the Mid-Atlantic and parts of the Northeast where many busy hubs are located.

Data from FlightAware showed that on Tuesday morning, 843 flights within, into or out of the US were delayed and another 806 were canceled. Still, that's a major decrease from Monday's chaos when more than 8,000 flights were either delayed or canceled because of severe weather.

United Airlines was once again faring the worst of the American domestic airlines. About 12% of its schedule, or 338 flights, was canceled and another 3%, or 92 flights, was delayed as of 7 am ET. Republic Airways, which operates short-haul flights for American Airlines, Delta and United, had 17% of its schedule canceled (153 flights) but few delays.

The four US airports most affected Tuesday morning are all major hubs for either United or Delta: New Jersey's Newark Liberty, both of New York' City's airports (LaGuardia and John F. Kennedy) and Boston's Logan.

More than 40 million people in the Northeast and Central Plains are at risk of severe storms on Tuesday. The majority of people at risk are located in the Northeast, including Philadelphia and Washington, DC, where a Level 1 of 5 threat has been issued by the Storm Prediction Center. A level 3 of 5 threat of severe weather is highlighted for parts of Kansas and Oklahoma, including Wichita and Tulsa.

Scattered thunderstorms are again expected east of a cold front from the Mid-Atlantic into parts of the Northeast, leading to the possibility of even more flight delays and cancellations later.

Some of these afternoon storms could produce damaging wind gusts, and heavy rain from these storms could produce isolated instances of flash flooding, particularly over parts of southeastern New York, Delaware and Pennsylvania.