(Strong vertical shear between two air streams causing winds to blow faster at the upper level than at the lower levels, causing turbulence. Sometimes these turbulent waves are seen in clouds).
From the early days of aviation, it was realised that meteorological information is vital for both the planning and safe conduct of flights. Pilots need to be informed about meteorological conditions along the routes they take and at their destination aerodromes.
In the early 1980’s the International Civil Aviation Organization (ICAO) developed the requirements for the World Area Forecast System (WAFS) to meet the needs of global aviation for the seamless forecasting of upper air winds, temperatures and significant weather hazards.
Two World Area Forecast Centres (WAFCs) were established. One operated by the Met Office in the UK and the other by the National Oceanic and Atmospheric Administration (NOAA) in the USA. The regulations covering the content of the forecasts are described in the ICAO publication known as Annex 3 to the convention on International Civil Aviation – Meteorological Service for International Air Navigation.
The Met Office and NOAA are also responsible for making available the WAFS forecasts online using SADIS (Secure Aviation Data Information Service) and WIFS (WAFS Internet File Service).
These services provide:
- Global forecasts of upper winds and temperatures for flights throughout the world, helping to optimise safety and fuel consumption.
- Global significant weather (SIGWX) forecasts.
- Global OPMET data (TAF, METAR and SIGMET).
Weather hazards that affect aviation such as turbulence, icing and convective storms can have a big impact on the comfort and safety of a flight. Met Office meteorologists are continually working to develop our modelling capability to ensure that the best forecast is available.
Below is an example of a Significant Weather (SIGWX) Chart that is produced every six hours for the entire globe by our WAFC meteorologists. The weather hazards on the chart indicate to a pilot the types of weather they may encounter during their flight. On this chart turbulence, convective cloud, active volcanoes, and jet streams are all shown.
Global hazard fields
As well as the manually drawn charts we also produce global gridded data sets. Shown in respective order below, these visualise weather hazards such as convective cloud, clear air turbulence and winds at upper levels. These charts may be used as part of flight planning to understand how the weather may impact a flight.
Lauren Reid – Business Development Manager.