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Weather Home UK World Sports Coast and Sea Climate Change Features Understanding Weather Sport and Leisure Health and Culture History, Literature & Religion Science and Nature Coast and Sea Weatherwise About BBC Weather Site FAQ About the BBC	Jet Streams around the World

		A Polar Front Jet Stream is a strong band of winds in the upper atmosphere that effectively controls the weather in high latitudes in the northern hemisphere.	Key Points The Subtropical Jet Stream is located 30° north and south of the equator. The Equatorial Jet Stream is located 7° north of the equator. The Polar-Night Jet Stream forms 60° north during the winter. Also in this Series Jet Streams in the UK Also in BBC Weather Air Pressure High Pressure Fronts Disclaimer The BBC is not responsible for the content of external websites.

	It is the mechanism for forming high and low pressure systems at the surface of the Earth, and consequently has a major influence on the Atlantic depressions that bring the UK much needed year round rainfall. ... the jet stream will be situated further north ... giving drought conditions over much of the British Isles. Unfortunately, there is a possibility that when global warming starts to really accelerate through the second half of this century, the jet stream will be situated further north in the Summertime giving drought conditions over much of the British Isles. There are several other strong bands of winds, or jet streams, that blow in the upper atmosphere. One of these is located at about 30 degrees north and south of the equator and is known as the Subtropical Jet Stream. This one is not associated with any weather fronts and normally sits above the semi-permanent high pressure systems giving strong and quite persistent westerly winds. ...Equatorial Jet Stream, is quite different from the others in that it blows as an easterly wind... Further south, at about 10 degrees north, or some 600 to 1000 miles, of the equator and extending from Asia across to Africa, is another strong band of winds. This, the Equatorial Jet Stream, is quite different from the others in that it blows as an easterly wind at a height of about 50,000 feet. The Equatorial Jet Stream comes and goes and is at its strongest during the northern Summer months of July and August. It is formed because of a large temperature change at those levels with the coldest air nearest the equator. It only blows from Asia across Africa and does not extend across the southern Atlantic. Underneath this jet stream, during the same Summer months, another jet stream sometimes forms over Africa. It is much lower in the atmosphere, around 12000-15000 feet and weaker than the Equatorial Jet Stream, but it can influence the weather quite dramatically over the southern Atlantic and Caribbean. It is around this jet stream that huge thunderstorms can form and as these move westwards across the southern Atlantic, away from the African continent, some of them develop further. If the atmospheric conditions are right, and the sea temperature is at least 27 degrees Celsius (80 degrees Fahrenheit) it could be the start of a hurricane. It is fascinating to watch these large storms on the satellite pictures as they form over West Africa and move out to sea on the easterly winds. Finally the Polar-Night Jet Stream, which as its name implies, forms during the winter at around 60 degrees north at a height of about 80,000 feet above the surface. In fact it is the direct opposite of the Equatorial easterly jet that forms during the northern hemisphere's Summer. All in all the jetstreams that circle our globe are very important to the meteorologists. Weather maps showing the position of the polar jetstream are often shown on weather forecasts in the USA.

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Jet Streams around the World