A monster storm started to wreak havoc Saturday across parts of the country, with 12,200 weekend flights and counting canceled. Forecasters warned that catastrophic damage, especially in areas pounded by ice, could rival that of a hurricane.

Here’s a guide for winter travelers as flight disruptions pile up:

Keep an eye on weather forecasts

When airlines expect bad weather to create problems for flights, they often give travelers a chance to postpone their trips by a few days without having to pay a fee. Search online for your airline’s name and “travel alerts” or similar phrases to look for possible rescheduling offers.

American Airlines, for example, said it is waiving change fees for passengers impacted by the storm and adding extra flights around the country in an effort to help passengers reach their destination after the storm passes.

Check before going to the airport

Use the airline’s app to make sure your flight is still on before heading to the airport.

Cancellations can happen hours — or even days — before departure time. Consider American and Delta Air Lines: By mid-day Saturday, each carrier had canceled more than 1,000 of its scheduled Sunday flights, according to flight tracking site FlightAware.

Oklahoma’s largest airport suspended all flights Saturday, while Dallas–Fort Worth International Airport, a major hub, saw more than 700 departing flights canceled and nearly as many arriving flights called off. Flight disruptions also were stacking up at airports in Chicago, Atlanta, Nashville and Charlotte, North Carolina.

Disruptions were expected to intensify Sunday, FlightAware data showed. By late Saturday afternoon, nearly all departing flights scheduled to leave Ronald Reagan Washington National Airport on Sunday — 405 flights, or about 95% — had already been canceled. Major disruptions were also forecast for airports in Charlotte and Atlanta, home to the nation’s busiest airport, as well as New York’s John F. Kennedy International Airport and LaGuardia Airport, where 87% of Sunday’s departing flights have so far been canceled.

My flight was canceled, now what?

If you’re already at the airport, get in line to speak to a customer service representative. If you’re still at home or at your hotel, call or go online to connect to your airline’s reservations staff. Either way, it helps to also research alternate flights while you wait to talk to an agent.

Most airlines will rebook you on a later flight for no additional charge, but it depends on the availability of open seats.

Can I get booked on another airline?

You can, but airlines aren’t required to put you on another carrier’s flight. Some airlines, including most of the biggest carriers, say they can put you on a partner airline, but even then it can be a hit or miss.

Am I owed a refund?

If your flight was canceled and you no longer want to take the trip, or you’ve found another way to get to your destination, the airline is legally required to refund your money — even if you bought a non-refundable ticket. It doesn’t matter why the flight was canceled.

The airline might offer you a travel credit, but you are entitled to a full refund. You are also entitled to a refund of any bag fees, seat upgrades or other extras that you didn’t get to use.

When will I get my refund?

If you paid with a credit card, a refund is due within seven business days after you decline an offer from the airline for another flight or a voucher, and within 20 calendar days if you paid for the ticket with a check or cash, according to the U.S. Department of Transportation.

What else will my airline cover?

U.S. airlines aren’t required by the Transportation Department to compensate passengers for meals or lodging when an airline cancels or significantly delays a flight during an “uncontrollable” event like bad weather.

Each airline, however, does have its own policies for assisting passengers who are stranded by a so-called “controllable” flight cancellation or long delay. These include disruptions caused by maintenance issues, crew shortages or computer outages that halt operations. The Transportation Department can hold airlines accountable for these commitments and maintains a website that lets travelers see what each airline promises if a major disruption is their fault.

Other tips

If the weather forecast is troubling, Kyle Potter, executive editor of Thrifty Traveler, suggests looking into booking a backup flight. Some airlines stand out as potential backups, Potter says, because they let customers get a full refund as long as they cancel within 24 hours of booking.

The customer service phone lines will be slammed if flight cancellations and delays start stacking up during a bad storm. If you’re traveling with someone who has a higher frequent-flyer status, call the airline using their priority number. Another trick: Look up the airline’s international support number. Those agents can often rebook you just the same.