HOUSTON (KIAH) It’s another day of canceled flights for Southwest Airlines leaving passengers at airports like Houston Hobby stranded.

The carrier blames wintry weather in parts of the country over the holiday weekend for what they call an “unacceptable” situation.

Getting out of the situation will apparently necessitate more cancelations.

“As we continue the work to recover our operation, we have made the decision to continue operating a reduced schedule by flying roughly one third of our schedule for the next several days,” a statement from Southwest read.

An air travel expert says wintry weather itself can keep planes grounded, but it can also lead to aircraft and their crews getting stuck in certain locations when they were due to fly in others.

But Janine Iannarelli, president and founder of Par Avion Ltd., says other factors could be at play as well.

“I’m making an assumption, but I think it’s a logical one,” she said. “It’s certainly a factor that’s come into play in the past. There might be some other things that are feeding into this problem that the airline is doing their best to manage from what I can tell. I’m sure we’ll hear some messaging especially since the government got involved.”

The U.S. Department of Transportation vowed Monday to investigate why Southwest canceled far more flights than any other airline over the holiday weekend.

Stranded passengers are still unsure if Southwest will reimburse them for expenses the cancelations have caused them like unexpected hotel stays.

The airline has set up a website to help them rebook flights or request a refund.