A massive winter storm is disrupting travel plans for tens of thousands of fliers trying to get home after Christmas. Snow, thunderstorms, sleet, tornados and high winds have grounded planes in the nation’s midsection and are expected to slow operations on the East Coast.

Delays racked up in the morning from Dallas to Indianapolis to Chicago. By 11 a.m. EST Wednesday, more than 600 flights nationwide had been scrapped, according to flight tracking site FlightAware.com.

More cancelations are likely throughout the day, with Washington, New York and Philadelphia expected to see the largest problems. For instance, wind gusts at New York’s John F. Kennedy International Airport could exceed 50 mph Wednesday night, according to FlightAware.

Passengers are pretty much at the mercy of Mother Nature and the airlines. But there are a few things they can do to improve their odds of getting home quickly.

• If you miss your connection, the airlines will automatically rebook you on the next available flight. However, with flights at near capacity, the next open seat could be several days away. Two years ago, some Christmas fliers had to wait nearly a week to get home.

• If you’re unhappy with your rebooked flight, get in line to speak to a customer service representative. But also, pick up the phone and call the airline directly, go onto the airline’s website and even consider sending a Tweet.

• Consider buying a one-day pass to the airline lounge. It’s a nice place to relax away from the crowd and there are usually free drinks and small snacks. But the real secret to the lounges is that the airline staffs them with some of its best – and friendliest – ticket agents. The lines inside will be much shorter and these agents are magically able to find empty seats where nobody else can. One-day passes typically cost $50.