We often talk about the jet stream and its impacts on UK weather – but it can have an even more direct effect on aviation as covered in the media in recent days.
The jet stream is a band of fast moving winds high up (around 5-7 miles) in the atmosphere. It usually travels eastwards around the northern hemisphere but regularly changes its track and strength.
Pilots travelling east, say from the US back to Europe, use the jet stream to cut journey times and save fuel – just like a cyclist uses a tailwind on a bike.
This has always meant journey times in the northern hemisphere are faster when travelling east than heading west (when airlines avoid the jet stream).
Recently the jet stream has been particularly strong over the north Atlantic, with winds of more than 250mph being seen at times.
This has had an impact on flying times – with eastbound trans-Atlantic services arriving well in advance of their scheduled times. Some types of passenger aircraft have reputedly seen record breaking journey times.
All this of course has a knock-on effect for airports as schedules are carefully planned to ensure there’s room, not to mention boarding gates, for each aircraft when it’s due to land. That has meant the strong jet stream creates a logistical challenge for airports across Europe.
The Met Office has been helping airlines and airports to plan ahead with its forecasts of the strength of the jet stream through its role as a World Aviation Forecasting Centre (WAFC).
There are only two WAFC centres in the world; the UK and Washington, in the US. The two centres provide aviation charts for the globe, highlighting conditions between 10,000 and 63,000 feet.
These charts show the location and strength of the jet stream, as well as other important aviation factors, such as clear air turbulence, cumulonimbus (storm producing) clouds, volcanoes and tropical storms. Both centres operate 24 hours a day and throughout the year.
Airlines use our upper-air wind forecasts to predict flight times at cruising altitude. For transatlantic flights during 2012, the average difference between the predicted flight time and the actual flight time was about one minute. This means that our aviation customers can accurately calculate the fuel load required for each flight. Our WAFC charts save airlines globally £2.7 billion a year because our forecasts help them fly safely and efficiently.
Accurate forecasts enable pilots, airlines and airports to assess flying times in advance and use that information to try to ensure things run as efficiently as possible on the ground.
© Met Office
