SADIS WAFS Gridded Data service 1.0.0
Current JSON

Abstract

The SADIS World Area Forecast Service (WAFS) Gridded Data service (the Service) supplies tiles of meteorological gridded data in response to tailored API requests submitted by an end user. This data is provided under the remit of the International Civil Aviation Organisation (ICAO) and can be used to support activities related to aviation.

The Service is operated by the Met Office in its role as World Area Forecast Centre (WAFC) London, and is primarily available to users located in Europe, Africa, the Middle East, and Asia.

WAFS data sets can be used for:

  • Flight planning (and therefore reducing fuel burn) 
  • Reducing C02 emissions 
  • Hazard awareness and avoidance

The Service is provided in accordance with ICAO Annex 3 – Meteorological Service for International Air Navigation and, from November 2025, the PANS-MET – Procedures for Air Navigation Services – Meteorology (Doc 10157).

The data sets include wind (u, v), temperature, relative humidity, geopotential height, max wind (u,v and height) and tropopause (height and temperature) from both WAFC London and WAFC Washington, and the harmonised WAFS icing severity, cumulonimbus and turbulence severity data sets.

  • 0.25-degree horizontal resolution data sets are available for all parameters, and the forecast extends 48 hours for the icing, cumulonimbus, and turbulence data sets, and either 66 or 120 hours for the rest.
  • Data is provided in flight levels at 1000ft vertical intervals between the following ranges: FL050 to FL600 for wind/temperature/geopotential; FL050 to FL180 for relative humidity; FL050 to FL400 for icing severity; and FL100 to FL450 for turbulence severity.
  • A subset of data is also available at a 1.25-degree horizontal resolution for wind (u,v), temperature, relative humidity, geopotential height, max wind (u,v and height), and tropopause (height and temperature) with a limited set of vertical levels out to 36 hours. This data is provided for users who struggle to use the higher resolution data set.
  • All forecast data is provided in GRIB2 format.

The Service organises the WAFS data sets into collections that allow users to request data for specific parameters, tiles and forecast timesteps. Global coverage “tiles” as well as 8 regional tiles are available for a range of forecast timesteps, and a new set of data is published every 6 hours.

The Service is part of the SADIS API family of offerings developed by the Met Office, which use the Open Geospatial Consortium Environmental Data Retrieval (OGC-EDR) framework. SADIS APIs also include:

  • SADIS OPMET API
  • SADIS SIGWX API

In the event of operational issues, the WIFS API operated by WAFC Washington is available for backup purposes. The SADIS and WIFS API offerings have been harmonised to make this easier. Information on the WIFS API is available here: https://aviationweather.gov/wifs/ and users will need to register separately to access it.

Furthermore, SADIS FTP also provisions WAFS gridded data sets for existing qualified users to download until its retirement in 2028.

 

Available from March 19, 2024.

Service Type
SWIM_COMPLIANT
Life Cycle
OPERATIONAL
Business Activity Type
AIRSPACE_ORGANISATION_AND_MANAGEMENT
Intended Consumer
AERONAUTICAL_INFORMATION_SERVICE_PROVIDER
AIR_TRAFFIC_SERVICE_PROVIDER
CIVIL_AIR_NAVIGATION_SERVICE_PROVIDER
CIVIL_AIRSPACE_USER
NETWORK_MANAGER
PROVIDER_OF_DATA_SERVICES
REGULATED_METEOROLOGICAL_SERVICE_PROVIDER
Information Exchange Category
AERONAUTICAL_INFORMATION_EXCHANGE
METEOROLOGICAL_INFORMATION_EXCHANGE
Application Message Exchange Pattern Entity
SYNCHRONOUS_REQUEST_REPLY
State ICAO Nationality Letters
EGRR
ICAO Region
EUR
Geospatial Categorisation Description
Worldwide coverage based on gridded forecast data.
In-Operation Date
19-Mar-2024
Provider
Met Office

The Met Office is the sole Air Navigation Service Provider (ANSP) certificated by the UK Civil Aviation Authority to provide and disseminate a range of aviation forecast products and services, in accordance with ICAO Annex 3 to the Chicago Convention, Meteorological Service for international Air Navigation.

ICAO’s Annex 3 provides the main regulatory framework against which the UK is obliged to provide meteorological services, and which the Met Office delivers Met Services against. This ensures that the UK meets its obligations to ICAO to provide safe, efficient and regular air travel.

These services fall into the following main categories:

a) UK services.

b) The World Area Forecast System (WAFS), as provided by World Area Forecast Centre (WAFC) London, in coordination with WAFC Washington.

c) SADIS (Secure Aviation Data Information Service).

d) The Volcanic Ash Advisory Centre (VAAC) London.

In addition to the ICAO Annex 3 determined services, a range of discretionary services that are determined as a requirement in the UK are also provided. Specific services such as Aviation R&D and the provision of information to NATS are examples of this.

Provider Type
REGULATED_METEOROLOGICAL_SERVICE_PROVIDER
Support

To report incidents on services in operation, contact the 24/7 Weather Desk at [email protected] or +44 330 135 0000.

Point of Contact
Operational need for SADIS WAFS Gridded Data

The service is provided in accordance with ICAO Annex 3 – Meteorological Service for International Air Navigation, and the PANS-MET – Procedures for Air Navigation Services – Meteorology (Doc 10157) from November 2025.

Data type

Aviation forecasts in GRIB2 format.

  • Data source: from either WAFC London or WAFC Washington.
  • Available as coverage "tiles" for the whole globe, or as one of 8 individual regional "tiles" representing approximately 1/8th of the globe.
  • Data sets are refreshed following model updates every 6 hours.
  • 'Main' data sets: wind (u, v), temperature, relative humidity, geopotential height, max wind (u,v and height) and tropopause (height and temperature):
    • at 0.25-degree out to either 66 or 120 hours, depending on model update.
    • at 1.25-degree resolutions out to 36 hours.
  • WAFS harmonised 'Hazards': icing severity, cumulonimbus and turbulence severity:
    • at 0.25-degree resolution, out to 48 hours.
OAUTH2 Client Credential/Bearer Token

Accessing the service is subject to prior approval by the SADIS Manager and agreeing to our terms and conditions. 

Access is based on OAUTH2 Client Credentials using Client ID and Secret to retrieve a Bearer Token. Login credentials must be set up in advance of first-time use.

Access to WAFC London's SADIS WAFS Gridded Data service does NOT include reciprocal access to WAFC Washington's WIFS Gridded Data service. Should you wish to access WAFC Washington's WIFS Gridded Data service, then you must apply directly via their website: https://aviationweather.gov/wifs/

Check Headers

The API makes use of standard HTTP headers, as specified in the SWIM Yellow Profile, WS Light Service Interface Binding.

Service Level Agreement

The WAFC London SADIS Manager periodically reports service performance and availability statistics to ICAO. 

Forecast data itself is verified by the Met Office Verification team annually.

To meet requirements from ICAO, Aviation Industry users and stakeholders, the Service is highly available: 

  • EDR API requests from qualified end users (authorised and authenticated via APIM) can be submitted at any time, and the Service will provision a response payload 24/7/365. 

  • The payload response of gridded data matches the item(s) requested by qualified end users (authorised and authenticated via APIM).

  • The payload response is complete i.e., it includes all vertical levels relevant for the requested parameter; a grid point has an accurate forecast value where appropriate. 

  • The WAFS gridded data sets should be available to qualified and authorised users via the EDR API no later than 5 hours after the nominal model run time. 

Capacity of Service

The service has been tested and passed to provision up to 550 unique users, requesting data payloads in GRIB2 format via API, within a 20-minute window at each model update at 6-hourly intervals: 2350-0010z, 0550-0610z, 1150z-1210z, 1750z-1810z.

Availability

The service updates 24/7/365. The Met Office Supercomputer generates new model updates every 6 hours, and the service only exposes forecast data from the latest model update. 

Performance is monitored via synthetic ‘canaries' against these availability targets measured per calendar month using Met Office download speed:

  • 99% of the time, a valid EDR API request from a qualified end user will be successfully fulfilled (i.e., returned the appropriate requested payload).

  • 99.2% of the time, a valid EDR API request from a qualified end user will be provisioned within 2 minutes.

Recoverability

Technical support is available 24/7, although on a 'best efforts only' basis outside normal working hours (08:00-17:30 GMT Monday to Friday, except Bank Holidays).

In the event of operational issues, we will instruct our users to access their usual data sets from the WIFS API, which is operated by WAFC Washington. Both SADIS and WIFS API offerings have been harmonised to enable this fail-over process.

SADIS FTP can also be used to provision WAFS data sets to existing qualified end users until 2028 when SADIS FTP will be retired.

Confidentiality

The Service adheres to SWIM Yellow Profile - Infrastructure Capabilities Binding requirements.

The system does not store or manage any personal data. Threat analysis confirmed that loss of confidentiality is deemed Low Risk.

Integrity

The Service adheres to SWIM Yellow Profile - Infrastructure Capabilities Binding requirements.

The Met Office also has robust Cyber Security protocols in place. In the unlikely event of a security breach impacting the integrity of the data, the service will be suspended, and we would notify users to fail over to WAFC Washington's WIFS Gridded Data service until security has been fully restored. 

SELF_VALIDATION
Validation

The service has been validated by numerous test activities including performance, data integrity, penetration and load tests. 

SWIM compliance implementation has been tested in accordance with guidance from the SWIM Yellow Profile 

APIM

API Manager - the API management platform used for Authentication and Authorisation that is integrated with the Service. APIM acts as the 'front door' of the Service for our users.

Collection

Means “dataset”. A set of forecast data for one or more related meteorological parameters.

Dataset

Means “collection”. A set of forecast data for one or more related meteorological parameters.

EGRR

The identifier code for the UK Met Office as the forecast originating centre. “EGRR data” refers to forecast data produced by the Met Office.

GRIB2

General Regularly distributed Information in Binary form. A file format for weather data, standard format for archiving and exchanging gridded data.

Gridded data

Forecast data based on a latitude/longitude grid. We provide this data at 1.25-degree and 0.25-degree horizontal resolutions.

ICAO

International Civil Aviation Organisation.

Item

A GRIB2 file returned from the /collections/{collectionId}/items/{itemId} endpoint, consisting of meteorological data for a specified parameter, region, and group of timesteps (the majority of our files include three timesteps each).

KWBC

The identifier code for the US National Weather Service as the forecast originating centre. Also referred to as NOAA (National Oceanic and Atmospheric Administration). “KWBC data” refers to forecast data produced by the USA.

Model run

A model run produces forecast data that we ingest. Our Supercomputer generates four model runs per day with the following model run times: 00Z, 06Z, 12Z, and 18Z (Z means UTC time).

NOAA

The National Oceanic and Atmospheric Administration; the forecast centre for the USA.

OGC

Open Geospatial Consortium. OGC is a consortium of experts committed to improving access to geospatial, or location information.

Parameter

A particular facet of meteorological conditions, e.g. “wind speed”, “temperature”.

SADIS

Secure Aviation Data Information System (SADIS), which supplies World Area Forecast System (WAFS) and OPerational METeorology (OPMET) data to aviation users in Europe, Africa, and parts of Asia. SADIS is delivered and maintained exclusively by the Met Office.

SADIS is a data library. It does not process/visualise data. It makes data available for extraction, processing and/or visualisation by end user systems.

Two versions of SADIS are currently available, the SADIS FTP (which will be retired in 2028) and the new SADIS API.

Tile

Refers to a geographical subset (or division) of the globe, which corresponds approximately to one eighth of the globe.

The service divides the globe in 8 'tiles' or regions. Depending on the API request, the service returns a payload of aviation meteorological data for the appropriate parameter and timesteps for the the desired regional/global tile. A global tile includes meteorological data for the whole globe.

Timestep

Means “forecast period”. A period of time for which forecast data is given, usually expressed as the number of hours after the model run time, e.g. T+6 means 6 hours after the model run time.

WAFC

World Area Forecast Centre.

The Met Office is one of only two World Area Forecast Centres (WAFC) and is known as WAFC London - the other is WAFC Washington (NOAA).

WAFS

Worldwide Aviation Forecast System.

WIFS

WIFS is the World Area Forecast System (WAFS) Internet File Service, a service provided by the United States to support international flight operations.

Information
SADIS WAFS Gridded Data service

The Met Office operates the SADIS WAFS Gridded data API service in its role as WAFC London, to support air navigation in Europe, Africa, the Middle East and Asia. The service supplies “tiles” of meteorological gridded data that match flight levels, in response to tailored API requests.

  • Data source: from either WAFC London or WAFC Washington.
  • Available as coverage tiles for the whole globe, or as one of 8 individual regional tiles representing approximately 1/8th of the globe.
  • Data sets are refreshed following model updates every 6 hours.
  • 'Main' data sets: wind (u, v), temperature, relative humidity, geopotential height, max wind (i.e. jet) and tropopause data
    • at 0.25-degree out to either 66 or 120 hours, depending on model update.
    • at 1.25-degree resolutions out to 36 hours.
  • WAFS harmonised 'Hazards': icing severity, cumulonimbus and turbulence severity
    • at 0.25-degree resolution, out to 48 hours.
TLS 1.2 

The service relies on HTTPS over TLS 1.2 to provide integrity and confidentiality. 

 

Service Monitoring for SADIS WAFS Gridded Data

The Service is monitored and has automated alerts that go to 24/7 Met Office support teams. However, no consumer visible monitoring capabilities are provided. 

The generation of forecast data and subsequent tile creation are triggered on the successful ingestion of requisite base components (push). Appropriate logging, monitoring and alerting are in place 24/7.

5-minute Synthetic Canary

A heartbeat service is used to periodically check the status of the Service and determine whether it is available. 3 synthetic canaries run every 5 minutes 24/7 and check the availability of these data sets as indicators:

  • EGRR Wind U and Wind V (2x parameters in the same file) at 0.25° resolution for a Global tile at timesteps T+6, T+7, T+8 and at timesteps T+54, T+60, T+66.

  • EGRR Cumulonimbus data (3x parameters – Base, Top, Extent) at 0.25-degree resolution in the A6 /North America at timesteps T+9, T+10, T+11 and at timesteps T+42, T+45, T+48.

  • EGRR Temperature (1x parameter) at 1.25° resolution in the A3/ Asia tile at timesteps T+6, T+9, T+12 and at timesteps T+33, T+36.

The synthetic canaries are not designed to check every possible combination of parameter, timestep and resolution. However, they have been selected to provide sufficient indication about the health of the Service and its underlying capabilities, and to orient any required investigation.

EDR Response codes
EDR Response Code Table
EDR Response code Code Meaning Impact and suggested actions
200 (OK) The request is successful. Expected behaviour, you can access the data.
302 (Found) Redirect status response code indicating that the resource requested has been temporarily moved to the URL given by the Location header.

Expected behaviour for retrieving {itemId} payloads. Follow this redirect to pick up your payload.
401 (Unauthorized Request) You are not authorised to access the service because our server requires user authentication. You cannot access the data due to invalid authorisation. Please check that your authorisation token is valid and has not expired, and try again.
403 (Forbidden) The request has been rejected because you do not have the rights to access or view the content. You cannot access the data due to invalid authorisation. Please check that your authorisation token is valid and has not expired, and try again.
404 (Not Found) The request is invalid. You cannot access the data because your request is not formulated correctly. Please check the validity of your request against the SADIS API - User Guide, Section 2.2 and Chapter 4.
408 (Request Timeout) The request you sent to the system took longer than the server was prepared to wait. You cannot access the data. Please try again. It is very unlikely that you encounter this error code. If the error persists, please contact our Support teams.
500 (Internal Server) While the request appears to be valid, the server failed to complete it. You cannot access the data. Please try again. If the error persists, please contact our Support teams.
502 (Bad Gateway) While the request appears to be valid, the server failed to complete it. You cannot access the data. Please try again. If the error persists, please contact our Support teams.
504 (Gateway Timeout) While the request appears to be valid, the server failed to complete it. You cannot access the data. Please try again. If the error persists, please contact our Support teams.
SADIS WAFS Gridded Data API

Provides tiles of meteorological gridded data in response to tailored API requests submitted by an end user. This data is provided under the remit of the International Civil Aviation Organisation (ICAO) and can be used to support activities related to aviation.

PROVIDER_SIDE
SYNCHRONOUS_REQUEST_RESPONSE
Operations
HTTP GET

The Service provides meteorological forecasts as GRIB2 response payloads. Within each request, consumers can specify a single 'item' (parameter) either for one global 'tile' (the forecast for the selected parameter for the whole globe per timestep group), or for one of 8 pre-set regional 'tiles'.

The Service also provides end users the ability to request metadata about the meteorological forecast included in the forecasts, returning a response in .json format.

Synchronous: Transactions are synchronous.

TI Protocol Method: HTTP GET

Precondition: Consumers must be authenticated and authorised via the Met Office API Management (APIM) Developer portal.

Processing consideration: The service shall provide only the latest available data.

Idempotent
IDEMPOTENT
Operation Message
HTTPS GET
GET /collections/{collectionId}

URL: https://gateway.api-management.metoffice.cloud/sadis-wafs-gridded-data/…/{collectionId}

Querying this end point returns metadata information in JSON format about one of these specific collections {collectionId}:

  • egrr_wafs_windtempgeo_0p25
  • egrr_wafs_humidity_0p25
  • egrr_wafs_tropjet_0p25
  • egrr_wafs_windtempgeo_1p25
  • egrr_wafs_humidity_1p25
  • egrr_wafs_tropjet_1p25
  • egrr_wafshzds_blended_ice_0p25
  • egrr_wafshzds_blended_turb_0p25
  • egrr_wafshzds_blended_cb_0p25
  • kwbc_wafs_windtempgeo_0p25
  • kwbc_wafs_humidity_0p25
  • kwbc_wafs_tropjet_0p25
  • kwbc_wafs_windtempgeo_1p25
  • kwbc_wafs_humidity_1p25
  • kwbc_wafs_tropjet_1p25
  • kwbc_wafshzds_blended_ice_0p25
  • kwbc_wafshzds_blended_turb_0p25
  • kwbc_wafshzds_blended_cb_0p25
Resource Type
REST_RESOURCE
Url

https://gateway.api-management.metoffice.cloud/sadis-wafs-gridded-data/…

GET /collections/{collectionId}/items

URL: https://gateway.api-management.metoffice.cloud/sadis-wafs-gridded-data/…{collectionId}/items

Querying this end point returns metadata information in JSON format listing the available items, each with an 'itemId' and its associated metadata, that can be requested from a specified collection {collectionId}.

The 'itemId' naming standard is described in section 4.1 of the SADIS API - User Guide.

Resource Type
REST_RESOURCE
Url

https://gateway.api-management.metoffice.cloud/sadis-wafs-gridded-data/…

GET /collections/{collectionId}/items/{itemId}

URL: https://gateway.api-management.metoffice.cloud/sadis-wafs-gridded-data/…{collectionId}/items/{itemId}

Querying this end point with the 'itemId' within a specified collection {collectionId} returns forecast data and associated metadata for this parameter e.g. Temperature, Geopotential Height, Relative Humidity, etc.

The success response is a 302 redirect, which directs you to the GRIB2 file payload of the requested item. The item payload contains the forecast data for all pressure levels for the relevant forecast timesteps and parameter(s), as specified by the 'itemId'.

The 'itemId' naming standard is described in section 4.1 of the SADIS API - User Guide.

Resource Type
REST_RESOURCE
Url

https://gateway.api-management.metoffice.cloud/sadis-wafs-gridded-data/…

WS Light

The Service Interface Binding is SWIM Yellow Profile Compliant, using WS Light enabling HTTP GET requests and associated responses.

  • The Service shall return a .json response for metadata requests:
    • OpenAPI:
      • / gets the EDR root data entrypoint
      • /api gets the EDR spec for exposed endpoints
    • /conformance gets the conformance data for the API
    • Collections data:
      • /collections gets the end point that contains information about all the collections available
      • /collections/{collectionId} gets the end point that contains information about an individual collection {collectionId}
    • Item data: /collections/{collectionId}/items gets the end point that contains information about items available in an individual collection {collectionId}
  • Request for meteorological forecast data shall return a response as a 302 URL redirect to the GRIB2 payload:
    • Item data: /collections/{collectionId}/items/{itemsId} gets the end point for forecast data contained in the {itemId} item from an individual collection {collectionId}
IPV4_SECURE_UNICAST

The Service implementation conforms with IPV4_SECURE_UNICAST as part of SWIM Yellow Profile requirements.

References
Revision Save Date
Tue, 03/19/2024 - 18:14
Schema version
v2