AMOSSG/4-SN No. 7

13/6/03

AERODROME METEOROLOGICAL OBSERVING SYSTEMS STUDY GROUP (AMOSSG)

FOURTH MEETING

Montreal, 15 to 18 September 2003

Agenda Item	5:	Aerodrome observation requirements
5.1:	Reporting requirements and criteria

OPERATIONALLY DESIRABLE ACCURACY OF FORECASTS

(Presented by Pete Woveris)

SUMMARY
A re-assessment of the operationally desirable accuracy of forecasts is presented in order to update the information provided in Attachment E to Annex 3.

1.	INTRODUCTION

1.1	At the AMOSSG/3 Meeting the International Air Transport Association (IATA) was tasked with providing a re-assessment of the operationally desirable accuracy of meteorological forecasts for civil aviation.

2.	DISCUSSION

2.1	The Meteorological Working Group (METWG) of IATA has provided a user opinion of the operationally desirable accuracy of meteorological forecasts for civil aviation in the form of an update to Attachment E to Annex 3 — Meteorological Service for International Air Navigation. This updated table is reproduced as the attachment to this study note.

2.2	It should be noted by the group that if Amendment 73 to Annex 3 is adopted by the ICAO Council then the current Attachment E to Annex 3 will become Attachment B. Some editorial changes would also be introduced concerning the titles of the first two sections, namely "AERODROME FORECAST (TAF)" would become "TAF" and "LANDING FORECAST" would become "TREND FORECAST". These editorial changes will be accommodated by the Secretary as appropriate following the adoption, or otherwise, of Amendment 73.

3.	ACTION BY THE GROUP

3.1	To discuss the suggested amendments to the attachment that relate to aerodrome forecasts.

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