Massive snowstorms in the U.K. have closed the country's two major airports as the Christmas season arrives. Both Heathrow and Gatwick in London have been closed and are scheduled to open later in the day. Over the rest of Europe expect cancellations and delays.

The latest Brand Passion Index measures consumer insights around popular airline brands American Airlines, Delta, Jet Blue, Southwest, United Airlines, and Virgin America for the busy traveling season. The passion results: Most positively passionate customers = Virgin America; most passionately negative customers = Delta; mixed bag = Southwest.