"Weather issues...."

American Airlines canceled another 634 flights on Sunday, nearly one in every four of its flights for the day, according to data from flight tracking website FlightAware. 

The airline has now canceled more than 1,500 flights since Friday, as it deals with weather issues and staffing shortages that started last week.

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Here's a radar shot of Sunday's weather from Ventusky.com:

Here's Saturday's:

The article claims high winds around Dallas, but this same site shows wind speeds of 5 mph with gusts up to 13 mph on Saturday and Sunday.