Understanding aviation MET products

METAR decode 

Familiarise yourself with the abbreviations used in METARs, that summarise the current weather at aerodromes in near real time. 

METARs are routinely issued at over 50 UK airports. They provide a snapshot of current weather conditions including wind speed and direction, visibility, weather, cloud, temperature and pressure. 

METARs are provided in a coded form, so to be able to fully interpret these messages, an understanding of what these codes mean is very useful. A decode for METARs is available here. 

TAF decode 

Familiarise yourself with the abbreviations used in TAFs that convey the most likely weather conditions over periods up to 30 hours ahead. 

TAFs are airport weather forecasts. They provide a concise description of the wind, visibility, cloud and weather conditions over periods ranging up to 30 hours ahead. 

TAF are routinely provided for over 50 UK airports. Like METARs they are provided in a coded format to ensure their content is broadly consistent with TAFs issued anywhere in the world. 

A decode for TAFs is available here. 

F215 decode and worked example 

Understand how to interpret low level aviation area forecasts to ensure awareness of the expected weather along your route. 

Low level aviation area forecasts (commonly known as a F215) are area weather forecasts provided specifically for UK general low level aviation. These charts are issued four times per day and can be used to show areas of poor visibility, and low cloud that pilots may wish to avoid along their flying route, and much more. 

It is said that it is possible to experience four seasons in one day in the UK. Our weather means that we also often see an incredibly wide range of weather conditions over the UK at any one time. The F215 forecasts therefore have to convey a great deal of weather information on a single page, so abbreviated plain language is used. Pilots can learn more about the content of these forecasts and the abbreviation used here, as well as a worked example. 

Guide to aerodrome warnings 

Learn about the weather hazard warnings issued by the Met Office to UK aerodromes. 

Aerodrome weather warnings provide a top level alert of specific aviation hazards likely to affect aerodromes across the UK. These include strong winds, gales, thunderstorms, hail, fog and frost and are generated for over 100 aerodromes. Learn more about aerodrome weather warnings. 

Briefing for balloonists 

A wide range of weather information is available to available to support balloonists plan and operate safely. 

Balloonists are particularly sensitive to the weather, so a robust approach to weather briefing is important to ensure that flights are carried out within operational limits. 

As well as a wide range of briefing material provided for the wider general aviation community, site specific ballooning forecasts are also available to provide additional information of specific interest to balloonists, such as thermal strength, windshear and temperature inversions. 

The Met Office and Civil Aviation Authority (CAA) have provided guidance on using the ballooning forecasts in this PDF document. 

What do Terminal Areas Forecasts (TAFs) actually mean?  

The values provided in TAFs are commonly thought to represent the exact forecast conditions for a particular time. 

In fact, whilst those values are the most likely expected, they actually account for a range of potential values. These ranges are defined by ICAO and implemented in the UK. Change groups in the TAF exist to represent changes in the weather that are expected to occur outside of a particular range of values. 

The table here describes the range of wind, cloud and visibilities that TAFs cover, without a change group being included. 

Upper winds and significant weather 

Wind, temperature and weather information for pilots that fly at higher altitude. 

The Met Office is one of two World Area Forecast Centres (WAFCs) and is responsible for providing global upper air weather data which is routinely used by commercial airlines. Apart from commercial airlines, other aviation sectors, such as business jets, also often operate at relatively high altitude. Planning flights with the latest available wind, temperature and en-route weather hazards information is crucial to the safe and efficient operations at these altitudes. 

Guidance on interpreting the features commonly seen on these charts is provided here. 

The use of aerodrome weather warnings 

Find out more about making the best use of aerodrome warnings and how they differ from TAFs here. 

Smoke SIGMETS 

SIGMET is an abbreviation for Significant Meteorological Information and are weather reports of hazardous weather for aircraft. The Met Office is now producing SIGMETs in the event of a widespread smoke event, similar to that experienced by aircraft in October 2017. 

Find out more about our provision of Smoke SIGMETs. 

General Aviation METeorological forecast (GAMETs) 

GAMETs are text based regional forecasts, covering a 9-hour period, and describe a range of meteorological parameters (up to 15000 feet above mean sea level) 

GAMET FAQs provides a description of the GAMET service, and an example forecast is available.