Southwest Airlines experienced more flight delays and cancellations than other carriers as another winter storm in the northern U.S. disrupted flight travel across the country early Wednesday.

According to data from FlightAware, Southwest Airlines was leading all carriers in cancellations or delayed flights, with a total of 411 early Wednesday. Delta Air Lines was also heavily affected, with a total of 378 delayed or canceled flights; by Wednesday afternoon, it had pulled ahead of Southwest for the volume of flights affected.

Regional carrier SkyWest Airlines, which operates flights for United, Delta and American airlines, among others, was the third most affected, with 295 delayed or canceled flights.

An alternative flight tracking site, Anuvu, which also measures delays and cancellations, showed Southwest and Delta tied for worst on-time departure rate as of Wednesday morning, at just 56%. Delta had the highest cancellation rate, at 10%, compared with Southwest’s 6%.

FlightAware showed that the airport most affected by the storm was Minneapolis-Saint Paul, a hub for Delta that is also served by Southwest, with 44% of flights canceled Wednesday. Denver International Airport, a hub for Southwest, was also heavily affected, with 11%, or 100 flights, canceled and 58 flights, or 6%, delayed. Other airports served by Southwest that were affected by the storm include Detroit Metropolitan, Chicago Midway and Salt Lake City International.

Southwest and Delta have both issued flight waivers for travelers potentially affected by this week’s storm that will allow them to rebook without paying any additional charge.

In a statement, Southwest said it was proactively making schedule adjustments based on forecasts.

Capt. Casey Murray, a Southwest pilot and spokesperson for the Southwest Airlines Pilots Association, said in an interview that the precautionary cancellations are the result of Southwest’s ongoing issues with its procedures, especially related to staff scheduling. At Southwest, crew members must manually call in about their availability, rather than notify the carrier electronically; Southwest is negotiating changes to the procedure with the pilots union.

‘It’s about how this airline connects crews to airplanes, and that still is not being addressed,’ Murray said.

Southwest is still dealing with the fallout from a 2022 Christmas weekend winter storm meltdown that saw at least 2 million travelers’ flights canceled and that cost the airline at least $800 million. Southwest has commissioned a study to determine what went wrong but has preliminarily blamed a combination of technical and procedural factors. Its COO also told a recent Senate hearing that the carrier’s winter weather preparedness was inadequate.

Tips for rebooking a flight

To avoid being trapped in a line to rebook at your airline’s terminal, get on the internet immediately and start looking for alternative forms of travel. Experts say Google’s flight search option is the best bet for finding the most up-to-date choices when it comes to getting a new flight, which are also searchable by a number of criteria, including price.

If you’re strapped for cash and are looking to rebook, you’ll still want to attempt to call the airline before or as you wait in line for an in-person rebooking agent. Of note: Not all major airlines have rebooking agreements with other carriers. The ones that do are: Alaska, American, Delta, Hawaiian, JetBlue and United. The ones that do not are: Allegiant, Frontier, Southwest and Spirit.

What your rights are if your flight was canceled

In this situation, you are only entitled to a refund if you don’t take an offer to be rebooked on another flight. That also means you don’t have to accept an airline’s offer of a voucher. According to the Transportation Department: “If an airline cancels a passenger’s flight or makes a significant change in the flight, regardless of the reason, airlines are required to provide a prompt refund to a ticketed passenger, including those with non-refundable tickets, should the passenger choose not to accept the alternative offered, such as rebooking on another flight.”

Unfortunately, you have few rights if your flight is delayed or canceled for reasons outside of an airline’s control

According to the Transportation Department website, only factors like maintenance or crew problems, cabin cleaning, baggage loading and fueling count as within an airline’s control.

If your flight was delayed for three hours or more or if it canceled and you have to wait at least three hours for a new flight, you are entitled to a meal, meal cash or a voucher and, with the exception of Frontier Airlines, are entitled to complimentary hotel accommodations and complimentary ground transport to and from a hotel for an overnight cancellation situation. Click here for more.

If your flight is delayed for any other reason, like weather, you are not entitled to any compensation or refund.