What is a jet stream?

1st February 2017 Last updated at 10:48

Jet streams drive weather systems worldwide and the UK has some of the most variable weather due to its location under a jet stream. But what are jet streams and how do they form?

Illustration of a typical jet stream
BBC
Illustration of a typical jet stream

A jet stream is defined as a narrow zone of high-speed winds. They can extend several thousand miles long.

Jet streams are typically found about 30,000 feet up in the atmosphere and are formed through significant temperature differences between conflicting air masses.

The ribbons of strong winds influence global weather patterns and their positioning helps meteorologists to forecast the weather.

With speeds of up to 200 miles per hour, jet streams are also important to pilots because flight time and fuel consumption can be affected greatly by flying either with or against them.

So, if on your travels, you've ever felt that your return flight seemed quicker than on the way out - your pilot could well have flown within a jet stream.