ICAO Annex 3, Chapter 2.1.3

Operational Need

Recommendation: Until 4 November 2020, METAR and SPECI should be disseminated in IWXXM GML form in addition to the dissemination of the METAR and SPECI in accordance with 2.1.2. (additional Note: this means the traditional alphanumeric codes format). As of 5 November 2020, METAR and SPECI shall be disseminated in IWXXM GML form in addition to the dissemination of the METAR and SPECI in accordance with 2.1.2. Note.— The technical specifications for IWXXM are contained in the Manual on Codes (WMO-No. 306), Volume I.3, Part D — Representation Derived from Data Models. Guidance on the implementation of IWXXM is provided in the Manual on the Digital Exchange of Aeronautical Meteorological Information (Doc 10003).