Service Name

Aerodrome Observation information service

Service Abstract

Weather observations give local weather useful for airport runways and other airport operations. The observation is an evaluation of meteorological elements that describe the state of the atmosphere either at the earth's surface. Specifically, the Aerodrome Observation information service provides continuous observations of weather parameters at set location(s) at an aerodrome. Most observations will be provided direct from the source instrumentation, with some human-made observations included manually as necessary.

Common Service Definition

The service definition for the Aerodrome Observation Information Service is currently under development by the MET3SG Task Team on Service Architecture. See Meteorological Aerodrome Observation Subscription and Request Service.

Service Implementation Status

The service is considered mandatory for all airports (currently publishing METARs). It is currently under development.

Service Information

A list of criteria for inclusion in the aerodrome observation information service shall be established by the meteorological authority, in consultation with the appropriate ATS authority, operators and others concerned.

However, the following elements shall be considered mandatory to include:

a) surface wind direction and speed (averaging period to be established, update frequency to be established);

b) visibility;

c) runway visual range, when applicable;

d) present weather, including intensity;

e) cloud amount, cloud type (only for cumulonimbus and towering cumulus clouds) and height of cloud base or, where measured, vertical visibility;

f) air temperature and dew-point temperature;

g) QNH and, when applicable, QFE.

Service Provision

Service Provider Organization

An aerodrome meteorological observation information service will be published for all aerodromes currently mandated to provide a METAR. Ultimately, this information service will supersede the current METAR provisions. The service provider organisation is the Aerodrome Meteorological Station designated by the Competent Authority for each aerodrome. This designation will vary depending upon local arrangements, but in most cases, the provider organisation will either be the airport, or the air traffic provider, or the MET ANSP.

Data Origination

The aerodrome observation information service will rely upon the information from the automated observation equipment/stations at the aerodrome, and in some cases the manual inputs from a human observer. 

Weather observation data is mostly used for the following purposes:

• METAR reports are provided at regular intervals (usually 30 minutes) and provide essential weather information about an aerodrome. Data should be representative for the whole aerodrome operating area.

• Special reports (SPECI) are be produced as dictated by the weather conditions (when there is significant deterioration or improvement in airport weather conditions, such as significant changes of surface winds, visibility, cloud base height and occurrence of severe weather). The criteria for the production of a special report and information dissemination are laid down in relevant local documents. The format of the SPECI report is similar to that of the METAR and the elements used have the same meaning. The identifier METAR or SPECI at the beginning of the weather report differentiates them.

• TAF (terminal area forecast) - the aerodrome forecast consists of a concise statement of the expected meteorological conditions at an aerodrome for a specified period.

• Automatic Terminal Information Service (ATIS) - is a continuous broadcast of recorded non-ATC aeronautical information.

• VOLMET - a worldwide network of radio stations that broadcast TAF, SIGMET and METAR reports.

• Weather reports to ATS. Weather reports to Air Traffic Services are usually issued half-hourly and are used by the ATS unit to provide weather information to operators, aerodrome users and pilots at or in the vicinity of the aerodrome. Whilst these reports are very similar to the METAR, there are slight differences in content and coding.

Provision Architecture

The aerodrome weather observations are defined as a the responsibility of the designated Aerodrome Meteorological Station.

The service can be discovered via the SWIM registry.

The service will be available as publish/subscribe

Service Consumption

Service Consumer Organization

An Aerodrome Meteorological Observation Information Service will be used primarily by:

• Air Traffic Service Providers

• Airspace Users including General Aviation and Business Aviation industries.

• Airports

• Aerodrome Meteorological Stations

Consumer Usage

• METARs are disseminated both to operators at the aerodrome concerned and where required internationally to all those who may need to use the airfield concerned. Meteorological information for international scheduled air traffic normally consists of documentation and if necessary briefing/consultation. The documentation is supplied to the pilot-in-command via self-briefing terminal or via airport operators.Air Traffic Service Providers

  • Updates to ATIS and VOLMET

  • Issuance of NOTAMS or SNOWTAMS

  • Local operating decisions such as runway changes or halting operations during adverse weather.

• Airspace Users including General Aviation and Business Aviation industries.

  • Operators, flight dispatchers, flight crew members and flight operations centres

  • Both in the pre flight planning phases and also updates enroute

• Airports

  • Local operating decisions for safety and efficiency i.e. snow clearance, de-icing, grass-cutting, re-fueling etc.

• Aerodrome Meteorological Stations

Sharing of observations to improve the accuracy and quality of forecasts.