International Civil Aviation Organization
WAFSOPSG/3-IP/3
9/8/06
THIRD MEETING
Paris, France, 26 to 29 September 2006
Agenda Item 5: Operation of the WAFS
5.3: Assessment of WAFS output performance indicators
DEVELOPMENT OF WAFS OUTPUT PERFORMANCE INDICATORS
(Presented by Australia)
SUMMARY
This paper addresses changes required to the WAFS output performance indicators for the Asia/Pacific Regions.
1.
INTRODUCTION
1.1
The meeting is aware that the two WAFC’s have made available performance indicators through the ICAO WAFSOPSG website.
1.3
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1.2
The information consists of RMS errors of temperature and wind vectors for 24 hours ahead at 0000 and 1200 UTC at a pressure level of 250 hPa, equivalent to flight level 340 (or
34 000 feet). The wind and temperature plots cover six different areas. Most of the areas are defined by the World Meteorological Organization Commission for Basic Systems to allow comparisons to be made between different modelling centres. A new area covering the north Pacific, as defined by ICAO, has been set up.
The areas are defined as:
North Atlantic (40N075W-70N090W-70N015E-40N000E)
North Pacific (30N120E-75N120E-75N120W-30N120W)
Asia (25N060E-65N060E-65N145E-25N145E)
Northern Hemisphere (30N-90N)
Tropics (30N-30S)
Southern Hemisphere (30S-90S)
(2 pages)
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2.
DISCUSSION
2.1
A number of users have requested information on the accuracy of WAFS wind and temperature forecasts in the Australia/New Zealand region. The performance information for Australia is contained indicators generated for the following areas; the southern hemisphere, and the tropics. This information is not focussed enough to provide users with an indication of WAFS performance over the
Australia/New Zealand area.
3.
PROPOSAL
3.1
In order improve the utility of WAFS performance information to airlines and air traffic management this paper proposes the monthly data be made available in either a chart/plot of the gridpoint values for the existing areas or the grid point values be provided for States to generate plots for their own area of interest.
3.2
Furthermore the availability of these data for all standard forecast levels provided by the
WAFS would be highly desirable.
3.3
The group may wish note that the issue was raised at the regional sub-group level, which formulated the following draft conclusion for consideration by the 17 th Meeting of the APANPIRG:
Draft Conclusion 10/20 –
Indicators
Further Development of WAFS Output Performance
That, the WAFSOPSG be invited to: a) include performance indicators for wind and temperature for the WMO defined verification area covering Australia and New Zealand, in their suite of existing output performance indicators; b) investigate the feasibility of producing the wind and temperature performance indicators for all standard levels; c) investigate the feasibility of producing the wind and temperature performance indicators in a global gridded and chart format; and d) develop WAFS output performance indicators for the SIGWX forecasts in order to measure the harmonization of these forecasts issued by the two WAFCs.
4.
ACTION BY THE WAFSOPSG
4.1
The meeting is invited to note the information in this paper and the fact that this conclusion is expected to be formally forwarded to the WAFSOPSG/4 Meeting for follow-up action.
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