The cliché about a "perfect storm" could hardly be a more apt description of the situation right now for Southwest Airlines — a carrier that has been forced to cancel more than 60% of its flights over the busy Christmas travel season as it struggles to get back on course after a devastating blizzard that socked in much of the United States.

While Southwest isn't the only airline to experience delays and cancellations, it is by far the worst-hit. More than 5,500 Southwest flights have been taken off departure boards across the country in the last two days, compared to 311 cancellations for Delta, which had the second-most cancellations by a U.S. airline.

Analysts say Southwest's problems are the result of a confluence of events — not just the severe weather, but staff shortages caused by the COVID-19 pandemic, as well as employees out sick with influenza and respiratory syncytial virus (RSV). Most important is an outdated computer system for crew scheduling that turned what would have been simply a challenging storm into a full-scale meltdown.

"In short, everything possible has gone wrong for Southwest, including some problems of their own making," says Kyle Potter, executive editor of Thrifty Traveler, a travel website. "At this point, we can very safely say that this is no longer a weather-related disturbance. We've had clear skies in the United States for several days now, more or less, and Southwest is the only airline that is failing so spectacularly here."

That failure has attracted the attention of Congress. On Tuesday, Sen. Maria Cantwell, D-Wash., chair of the Senate Committee on Commerce, Science, and Transportation, released a statement saying the committee would look into "the causes of these disruptions and its impact to customers."

For Southwest passenger Taylor McClain, 34, the saga started last Thursday, when his morning flight from Salt Lake City into Chicago Midway was canceled. He rebooked for a 3 p.m. that didn't end up departing until 9 p.m.

McClain's return to Utah has been even more harrowing. He was scheduled to leave Chicago late Monday. It was canceled. Now, the soonest he's been able to reschedule is for Thursday night.

At least he's lucky to be with his parents, but "I will burn multiple days of unplanned vacation and absorb four days worth of extra kennel fees for the dog I can't get back to," he says.

"It was awful. It really was," McClain says, adding that he feels bad for fellow Southwest passengers who face even worse predicaments.

He says he's flown Southwest for the past decade, but he will wait and see how the company makes him whole before deciding to fly with the airline again.

"Southwest needs to be held accountable for such a colossal failure," McClain says.

In a statement issued Monday, the airline said the "continuing challenges" to its operations impacting its customers are "unacceptable."

"And our heartfelt apologies for this are just beginning," Southwest said. "We recognize falling short and sincerely apologize."

The company said the severe weather had "forced daily changes to our flight schedule at a volume and magnitude that still has the tools our teams use to recover the airline operating at capacity."

Helane Becker, an aviation analyst with Cowen, an investment bank and financial services company, says Southwest needs to bring those tools, in the form of internal software systems, up to date.

"It's not only their customer-facing systems, it's their crew scheduling and so on," Becker says. "Southwest has always been a laggard when it comes to technology."

Another key factor is Southwest's heavily reliance on shorter, point-to-point flights, rather than a "hub and spoke" model of many of its largest competitors. In fair weather, it's a system that has worked well for them. But in inclement weather, it can cause problems, says Kathleen Bangs, a former commercial airline pilot and spokesperson for FlightAware.

Delta's big hub, for example, is Atlanta, while United filters many of its flights through Chicago.

With Southwest, however, "their pilots take off in the morning from one city, then they fly to two, three, four, five, six other cities. There's a flight crew change somewhere in there, and then it flies one or two more legs across the country and spend the night," Bangs says.

As a result, "when you get a weather situation like this, you have all sorts of pilots and flight attendants that can no longer get to where they need to be, because quite often flight crews are not based at the same city or they don't live at the same city that they're based out of," she says. "So when there's bad weather, everything tends to get out of position."

As a result, backfilling can be a nightmare.

Capt. Mike Santoro, the vice president of the Southwest Airlines Pilots Association that represents the airline's more than 10,000 pilots, said on CNN that the union was "tired of apologizing for Southwest. Our hearts go out to all of the passengers."

One of those passengers, Skyler Lenz, lives with his wife and two young children in Denver. The family was visiting New York City, where they were celebrating together — a wedding anniversary and his daughter's birthday.

The family flew out on the 21st, and planned to fly home on Christmas Eve. Just before they departed for the airport, Lenz checked his phone app "to make sure everything was good."

It wasn't good. The flight was canceled. He was on the phone for hours, but couldn't reach an agent. So, he used an app on his phone to rebook — for Dec. 28. He finally reached an agent on Monday. He asked, "Do you think this is going to be resolved by the time we fly out?"

The agent reassured him, and even moved the flight to the 27th. "But that's when everything started to get canceled," he says — including his Tuesday flight.

Finally, the family decided to rent a car and drive back to Denver — a 26-hour drive. "There's a place about halfway through in Illinois that's 13 hours from here and 13 hours from from Denver. So our goal is to take a quick breather at the hotel and then pick it up again so we can be there Thursday night," Lenz says.

As badly as things have gone for both Southwest and its customers, the company has owned up to its problems, says Becker. "From a PR perspective, they're out in front," she says. "They're saying they're buying meals for people, they're putting people up in hotel rooms. They're doing their best to get you where you need to go. They're reimbursing you. They're buying tickets on other airlines."

This time it's Southwest, but other airlines have had similar "operational meltdowns" in the past, notes Bangs.

In summer 2021, for example, it was Spirit and American. And over Memorial Day this year, it was Delta Air Lines.

"Unfortunately for Southwest, this holiday season has been their turn," she says.

But industry analyst Potter says the airlines' failures mean customers end up paying the price. And that will continue as long as the carriers are allowed to "keep running these razor thin margins where mass delays and cancellations [are] just a storm or a mechanics strike or an IT software issue away."