US airlines cancel flights for sixth day as omicron, weather wreaks havoc

U.S. airlines canceled more flights on Wednesday as an operational disruption caused primarily by the COVID-19 omicron variant continued for the sixth straight day.

With crews sidelined due to COVID infections, some airlines have had difficulty staffing flights. Additionally, Seattle (SEA) continued to see disruptions as airline networks recover after snowstorms. That recovery may be short-lived, as another 1-3" of snow is in the forecast for Thursday.

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As of 11:45 a.m. ET, U.S. carriers had canceled 791 flights, according to FlightAware.

SkyWest, the nation's largest regional airline, led cancelations for the second day in a row, with 192 flights, or 8% of its schedule. SkyWest flies for United Airlines, American Airlines, Delta Air Lines and Alaska Airlines.

United followed with 158 flights canceled (7% of its schedule), and then Delta, with 103 flights canceled (3% of its schedule). Both airlines have faced continuous woes since they began canceling flights operating on Friday, Christmas Eve.

In a statement on Tuesday afternoon, Delta blamed the weather at its hubs as the primary cause of the disruption.

"Winter weather and conditions in the Pacific Northwest, Midwest and the omicron variant are continuing to hamper operations, with Delta expecting to cancel upwards of 250 of 4,133 scheduled mainline and Delta Connection flights on Tuesday," it said.

Related: Delta warns of possible operational disruption caused by omicron quarantine rules, asks CDC to change guidelines

The Atlanta-based carrier has been in the news for publicly urging the Centers for Disease Control and Prevention to shorten COVID quarantine guidelines. On Monday, the CDC did just that, shortening quarantine from 10 to five days, though it's unclear how much relief that has provided to airlines thus far.

“The aviation workforce is essential to maintaining the operations of air travel and cargo supply chains. We appreciate the CDC’s announcement today updating isolation guidelines,” Airlines for America, the industry's lobbying group, said in a statement. “The decision is the right one based upon science.”

Despite the continued disruptions, there were some signs of improvement on Wednesday.

Southwest Airlines, which canceled 86 flights (2% of its schedule) on Tuesday, had only canceled nine flights by 11:45 a.m. ET.

American Airlines, which had been plagued by operational disruptions this fall, continues to operate relatively unscathed, as it has this entire week. Just seven flights had been canceled for the day by Wednesday morning.

Many of these cancelations have been proactive, meaning they're being decided strategically, many hours before the flight is scheduled to depart. If you are planning to travel in the next few days, it's important to monitor your email for important schedule updates from your carrier. Checking your reservation on your carrier's website or app doesn't hurt either, especially before you head for the airport, where lines can be long. Here's what to do if your flight is delayed or canceled.

Photo by Daniel Slim/AFP via Getty Images.