Dallas-based Southwest struggled to recover from a mammoth weekend storm, cancelling at least 16,000 flights since last Friday and leaving passengers as well as its own crews stranded during the busy Christmas holiday rush.

The airline showed 41 cancellations, or 1% of total flights, on Friday, according to flight data tracker FlightAware, far less than the nearly 60% cancellations on previous days.

Chief Executive Bob Jordan said he was confident the airline would run a very tight operation on Friday, and acknowledged a variety of factors that led to the company's nosedive.

"Let me just be straightforward here: the storm had an impact but we had impacts beyond the storm that obviously impacted Southwest very differently," Jordan said in an interview with ABC's "Good Morning America."

The challenge of moving crews around, keeping the airline running, could not be met by Southwest's regular operations and tools, he said, including the vast reach of the storm and shutdowns across so many cities as well as record cold temperatures that froze runways.

"This is something that we have really never seen in our 51 years," Jordan said, "There'll be lessons learned from this and we'll continue to make more investments."

The bitter weather was just part of the problem for Southwest. The airline's dated technology failed to map crews to flights and its point-to-point operational structure created chaos for schedules, the company has admitted and union members have said.

Southwest Airlines has promised to reimburse passengers for expenses such as hotels and car rentals in addition to refunding tickets and said there would be a still-undetermined hit to its earnings.

Transportation Secretary Pete Buttigieg in a letter to Jordan on Thursday warned that the company would be held accountable if it did not fulfill commitments to customers for "controllable delays and cancellations."

The Southwest chief executive said he had a "great conversation" with Buttigieg and their goals were aligned.