IWXXM (the ICAO Meteorological Information Exchange Model) is a data format for reporting aviation weather information in XML/GML, and is specified in both XML Schema and Schematron.
IWXXM includes XML/GML-based representations for products standardized in International Civil Aviation Organization (ICAO) Annex III and World Meteorological Organization (WMO) No. 49, Vol II, such as METAR/SPECI, TAF, SIGMET, AIRMET, Tropical Cyclone Advisory and Volcanic Ash Advisory. IWXXM products are used for operational exchanges of meteorological information for use in aviation.
Unlike the traditional forms of the ICAO Annex III / WMO No. 49 products (referred to as Traditional Alphanumeric Codes, or TAC), IWXXM is not intended to be directly used by pilots. IWXXM is designed to be consumed by software acting on behalf of pilots, such as display software.
Please provide feedback to or raise your question in Google group cbs-tt-avxml@wmo.int.
- IWXXM on WMO WIS Wiki
- WMO No.306 Volume I.3, Manual on Codes. Part D - Representations derived from data models
- ICAO Doc 10003, Manual on the Digital Exchange of Aeronautical Meteorological Information
The IWXXM translation repository has resources related to Traditional Alphanumeric Code (TAC) to IWXXM translation, including equivalent TAC/IWXXM pairs and a list of translation software.