Chart courtesy of meteociel.fr
Animated Jet Stream ForecastChart courtesy of squall.sfsu.edu
What is itThe jet stream is a narrow band of fast flowing air at high altitudes generally flowing from the west to east over the mid-latitudes and are caused by a combination of the planet's rotation on its axis and atmospheric heating (by solar radiation.
Jet streams are found at or just below the top of the troposphere, but the term is often wrongly used for all upper-level winds. Usually the jet stream marks the boundary between cold polar air to its north and warmer air to its south (northern hemisphere). The jet stream above the UK is called the Polar Jet Stream, its this Jet stream which is responsible for the UKs weather.
Recent news - February 2014New research suggests that the main system that helps determine the weather over Northern Europe and North America may be changing. The study shows that the so-called jet stream has increasingly taken a longer, meandering path. This has resulted in weather remaining the same for more prolonged periods. The work was presented at the annual meeting of the American Association for the Advancement of Science (AAAS) in Chicago by Prof Jennifer Francis of Rutgers University in New Jersey.
The observation could be as a result of the recent warming of the Arctic. Temperatures there have been rising two to three times faster than the rest of the globe. The meandering jet stream has accounted for the recent stormy weather over the UK and the bitter winter weather in the US Mid-West remaining longer than it otherwise would have.
“We can expect more of the same and we can expect it to happen more frequently,” says Prof Francis
Interesting factsDuring the summer the jet stream is usually to the North of the UK allowing high pressure from the atlantic to move in. However during the recent summers of 2007, 2008 and 2009 the jet stream was abnormally low in latitude, which caused the dull wet summers.
Meteorologists use the location of some of the jet streams as an aid in weather forecasting. The main commercial relevance of the jet streams is in air travel, as flight time can be dramatically affected by either flying against or with the flow of a jet stream which cuts flight time and saves fuel for the airline industry.
Charts produced by Digital Atmosphere
Big thank you for the Digital Atmosphere Jet Stream script by www.hebwx.co.uk
Page updated 16/2/2014