Southwest Airlines stock was falling Thursday after the airline posted a wider-than-expected loss in the fourth quarter and anticipated another loss in the current quarter.

The airline canceled more than 16,700 flights between Dec. 21 and Dec. 31 last year as bad weather displaced crews all over the country, leading the airline to operate a reduced schedule for a number of days.

The carrier reported a net loss of $220 million in the fourth quarter, or a loss of 38 cents a share, on revenue of $6.17 billion.

Analysts surveyed by FactSet were expecting a loss of 7 cents a share on revenue of $6.22 billion.

CEO Bob Jordan said the cancelations in December led to an $800 million pretax hit , and said the airline has "swiftly taken steps to bolster our operational resilience."

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However, the knock-on effects of the disruption, which saw Southwest issue a "heartfelt apology" and offer passengers 25,000 frequent-flier points, are still being felt.

In January so far, the company said it has experienced an increase in flight cancelations and a deceleration in bookings, largely for this month and February. The carrier said it assumed this was linked to the travel chaos in December.

As a result, Southwest said it expects a $300 million to $350 million revenue hit in the first quarter of 2023. Southwest sees another net loss in the first quarter.

The stock fell more than 5% Thursday and is now around 4% up so far in 2023.