Extraction of Aerodrome Forecast from TAF for VOLMET Broadcast
The new ICAO Annex 3 Standard requires that only one valid TAF could be issued at an aerodrome at any given time. Considering the time limitation of HF VOLMET broadcast and feedback from air traffic control personnel and pilots, the Observatory devised a method to address the user requirement while maintaining compliance to the Standard. In essence, aerodrome forecast with validity period of 9 to 12 hours will be extracted from the 30-hour TAF of VHHH for inclusion in the HF VOLMET broadcast and D-VOLMET. This method was finally adopted by ICAO in its guidance to States. This aerodrome forecast is also available on the AMIDS in abbreviated plain language (under HKIA MET Page).
Fig.1: Extracted aerodrome forecast in abbreviated plain language on the HKIA MET Page (not for official international exchange) on the AMIDS.