What does “CAT” mean, we asked you on our Facebook page. Here’s the answer:
Clear air turbulence (CAT) refers to the sudden occurrence of turbulence without any visible cloud activity.
It is commonly referred to as an “air pocket” even though this type of turbulence is not the result of a sudden drop in air pressure or the presence of an air vacuum. The cause is rather a rapid change in the speed and direction of air movement. CAT occurs when masses of air moving at differing speeds collide. The altitude at which this is most likely to happen is between 7,000 and 12,000 metres in the jetstream zone or at lower altitudes near mountain ranges.