New ICAO Requirements of Aviation Meteorological Services

The International Civil Aviation Organization (ICAO) regularly reviews the standard and recommended practices of aviation meteorological services (Annex 3) and makes regular amendments. The following changes in flight document service are implemented to meet the new requirements arising from Amendment 76 to Annex 3 effective on 14 November 2013:

• A full flight document package is introduced to provide forecast charts of upper level wind and temperature at 3 hourly intervals and prognostic significant weather charts at 6 hourly intervals;
• Make available forecast chart of upper level wind and temperature for FL410;
• Under the new requirement by Annex 3, TAF shall be issued not earlier than one hour prior to the beginning of its validity period; and
• Removing the need for reporting and forecasting of ice crystals in METAR/SPECI and TAF.

To ensure smooth transition, the Observatory briefed the airlines and pilots on these changes in the regular meetings of the Liaison Group on Aviation Weather Services.