How a strong jet stream is affecting aviation

13 01 2015

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.

You can find out more about the jet stream in our YouTube video:

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.





Overnight wind speeds – Wednesday 30 January

30 01 2013

Following Met Office amber weather warnings for wind in some parts of the UK yesterday, some high gust speeds were recorded late last night and into the early hours of the morning. The highest gust speed at lower levels was recorded at Fair Isle, Shetland which saw speeds of 86 mph this morning, while the highest gust recorded at a mountain site was 135 mph at Cairngorm Summit.

Max gust speed at lower level sites

Date/time Site name Area Elevation Max Gust Speed (mph)
30/01/2013 06:00 Fair Isle Shetland        57 86
30/01/2013 05:00 Lerwick Shetland        82 84
30/01/2013 07:00 Kirkwall    Orkney          26 82
30/01/2013 01:00 Loch Glascarnoch    Ross & Comarty 269 79
30/01/2013 01:00 Stornoway Airport Western Isles 15 78
30/01/2013 04:00 Wick Airport  Caithness    36 75
30/01/2013 00:00 South Uist Range   Western Isles 4 75
30/01/2013 00:00 Tain Range Ross & Cromarty 4 70
30/01/2013 05:00 Altnaharra Sutherland   81 68
30/01/2013 03:00 Wight: Needles Old Battery Isle Of Wight 80 68

Max gust speed recorded at mountain sites

Date/time Site name Area Elevation Max gust speed (mph)
30/01/2013 00:00 Cairngorm Summit Invernessshire 1237 135
30/01/2013 01:00 Aonach Mor Invernessshire 1130 110
30/01/2013 07:00 Cairnwell Aberdeenshire 928 105
30/01/2013 00:00 Bealach Na Ba Ross & Cromarty 773 101
30/01/2013 02:00 Glen Ogle        Perthshire 564 77

Warnings remain in place for wind in some areas, you can keep up to date with the latest severe weather warnings on our website.





Latest rainfall totals and wind speeds

26 11 2012

Below are the latest rainfall totals from 6.00 pm Sunday night until 6.00 am this morning.

Location Amount (mm)
Mona        27.8
Blencathra              27.4
Capel Curig    26
Valley         25.4
St Bees Head    20.8
Keswick  19
Ronaldsway 18.4
Blackpool 18.2
Rochdale   18
Aberdaron        17.4

The highest rainfall totals are now futher north, however as the table below shows, areas in the south west have seen the most rainfall overall. This is in addition to the rainfall totals from the 20th – 23rd November, where some areas saw in excess of 90 mm of rain.

Rainfall totals from midnight 24th November until 6.00 am this morning:

Location Total (mm)
Plymouth, Mountbatten                72
Scilly: St Marys Airport             66.6
Cardinham, Bodmin                    66.2
Dunkeswell Aerodrome                 60.8
Camborne                             59.6
Exeter Airport                       55.6
Fylingdales                          51.8
Culdrose                             49
Capel Curig                 49
North Wyke                           48.2

This video shows the rainfall from this period with satellite and rainfall radar imagery.

There were also some strong gusts of wind last night:

Location Max gust (mph)
Berry Head                 62
Wight: Needles Old Battery 59
Plymouth, Mountbatten      49
Isle Of Portland           48
Scilly: St Marys Airport   48
North Wyke                 45
Warcop Range               45
Langdon Bay                44
Solent                     44
Cardinham, Bodmin          44

Severe weather warnings are still in place for further rainfall today. Keep up to date with warnings and flood warnings from the Environment Agency.








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