AMOFSG/7-SN No. 14
22/5/08
AERODROME METEOROLOGICAL OBSERVATION AND FORECAST
STUDY GROUP (AMOFSG)
SEVENTH MEETING
Montréal, 9 to 12 September 2008
Agenda Item 6: Aerodrome forecasts
FUTURE TERMINAL FORECAST DEVELOPMENT
(Presented by Herbert Puempel)
SUMMARY
It is anticipated that an improved integration of meteorological information
within the flight planning and air traffic management process will benefit
aviation operators through increasing capacity at the busiest aerodromes while
preserving safety. This paper presents an overview of on-going actions to that
address terminal forecasts to meet this objective. This paper also seeks
agreement on the establishment of an ad-hoc working group to define the
operational service requirements of a modernized terminal forecast.
.
1.
INTRODUCTION
1.1
The Aerodrome Meteorological Observing and Forecasting Study Group (AMOFSG)
was formed by the International Civil Aviation Organization (ICAO) Meteorology (MET) Secretariat in
order to assist it in the development of the standards for Meteorological Service for International Air
Navigation. This study group is the successor to the Aerodrome Meteorological Observing Systems
(AMOS) Study Group and has carried forward its work program with the addition of an explicitly wider
scope to include forecasting topics.
1.2
The current aerodrome forecast product, in the form of the TAF, is not expected to
undergo major changes in either amendment 75 or 76 to Annex 3 — Meteorological Service for
(4 pages)
106737389
AMOFSG/7-SN No. 14
-2-
International Air Navigation . Although some updates can be expected, the primary change to the TAF
until probably 2016 will likely be the code change pending for November 2008 to accommodate TAF
with a 30-hour valid period.
1.3
The World Meteorological Organization (WMO) Commission on Aeronautical
Meteorology (CAeM) has organized Expert Teams (ET) to address various issues facing the WMO
Members providing services to civil aviation. The Expert Team on New Terminal Forecast (ET-NTF) was
tasked with developing a new terminal forecast for consideration by the next conjoint WMO CAeM
session/ICAO MET Divisional Meeting to be held in the 2013/2014 timeframe with a view to world-wide
adoption. This new terminal forecast will provide enhanced aviation weather to Air Traffic Managers in
an effort to improve safety and efficiency. The new forecast will provide weather information and
forecasts for the wider terminal area out to 150 nautical miles of the aerodrome — they area not
adequately covered by the TAF or by en route forecasts.
1.4
Close coordination between the WMO ET-NTF and the ICAO AMOFSG is essential in
order to ensure that this new forecast product is aligned with current and anticipated aeronautical
requirements.
2.
DISCUSSION
2.1
stated that:
The decision record from the sixth meeting of the AMOFSG, held in October 2006,
“The group noted that the WMO CAeM Management Group had made a proposal for
consideration by the forthcoming 13th Session of the CAeM that an expert team on the
future of aerodrome forecasts and TAF in particular be established. The group supported
the proposal in principle; however, it emphasized that the work of such an expert team
should principally relate to the development of methodology on how to meet the
aeronautical requirements stated by ICAO, in accordance with the Working
Arrangements between the International Civil Aviation Organization and the World
Meteorological Organization (Doc. 7475). Therefore, any proposals from the new expert
team which could be considered a candidate for a future requirement should be made
known to the (AMOFSG) for further assessment (as to whether it constitutes a genuine
aeronautical requirement). Furthermore, the group wished to encourage any WMO expert
team to not limit their deliberations to forecasts intended for flight planning (i.e. TAF)
but to consider the needs of ATM and other aerodrome users as developing technologies
could be considered by the (AMOFSG) in the light of the needs of all aeronautical users.”
2.2
The ET-NTF was established following the adoption of Resolution 3 from the 13th
Commission on Aeronautical Meteorological (CAeM-XIII), held shortly after the sixth meeting of the
AMOFSG. The team met in Hong Kong, China, in March 2007, to initiate development of the NTF.
Representatives from Australia, China, Hong Kong, China, France, Canada and the United States were
attending the meeting.
2.3
The ET agreed that a wide gap currently exists in weather forecast information between
the en route phase of flight and the aerodrome forecast. Further, the ET acknowledged many Member
States were addressing the gap in a variety of manners with respect to new products. The team concluded
that the time is right to address the gap and provide a standard type of product that can be supported by
the ICAO.
-3-
AMOFSG/7-SN No. 14
2.4
The ET also hosted several representatives from the airline industry to discuss industry
weather requirements. The industry representatives agreed that addressing this gap is important,
especially in areas where traffic is dense. Since the meeting, within the United States, the FAA has
requested the design and evaluation of a new Terminal Radar Approach Control (TRACON) forecast
which is similar to what is envisioned for the NTF.
2.5
After coordination with industry representatives and presentations from team
representatives, the ET reached consensus on the terminal area covered by the NTF. The terminal area is
defined as that portion of the airspace within the proximity of a controlled aerodrome within which
arriving and departing aircraft are managed to provide separation, assurance, appropriate arrival spacing,
appropriate departure spacing and final approach sequencing. Generally this distance will be no greater
than 150 nm and that the area covered between initiation of descent and landing, or 20 to 25 minutes prior
to landing. The most critical information required includes convection, wind profiles, icing and
turbulence. This information, combined with sophisticated arrival management systems in air traffic
control could help to ensure a smooth and continuous descent for aircraft.
2.6
The NTF should provide weather information for the critical phase of flight from the
beginning of descent through landing. The information should be presented in graphical form for easy
interpretation by any member of the aviation community. The NTF should also be provided in digital
form to allow users to ingest and display in the current and emerging weather information and decisionsupport systems.
2.7
The NTF should be provided on as fine a spatial and temporal resolution as possible.
The information should use shorter time steps (some fraction of an hour) out to 8 hours.
2.8
The science of meteorology can provide much more than a TAF currently allows.
This would include greater precision, and associated probabilities, in a format that can be directly
ingested by decision support systems. A wide variety of decision factors could be produced including:
a) parameters currently in the TAF;
b) quantitative precipitation rates;
c) runway surface condition;
d) runway visual range;
e) cross/head/tail wind components;
f) thunderstorms including quantitative details regarding lightning and hail size;
g) airframe icing on ground and along approach path;
h) wake vortices;
i)
low level wind shear;
j)
humidity ;
k) density altitude;
AMOFSG/7-SN No. 14
l)
-4-
temperature inversion and noise abatement information; and
m) forecasts extended beyond the 30 hour validity period.
2.9
It is currently projected that the NTF would be developed independently from the TAF
but would soon be used in addition to it. Suitable guidance material to support a prototype NTF, and the
concept of probabilistic forecasting in particular, is being planned for 2010 with possible formal
introduction into Annex 3 likely to follow in amendment 76 (November 2013). For the short to medium
term the NTF should be considered as a new forecast product targeted primarily to support Air Traffic
Management. The engagement of aviation decision makers must start immediately. The NTF should also
be seen as a step towards a net-centric data distribution system with increased flexibility of content,
resolution and accuracy.
3.
CONCLUSION
3.1
The optimum means to progress is through the formation of an ad hoc working group
would be an ideal first step in the development of a new terminal forecast. Such a working group would
have the participation of a suitable cross section of industry, WMO ET and AMOF perspectives. Such a
working group would ensure full coordination in the development of this new product in response to
clearly stated aeronautical requirements.
4.
ACTION BY THE GROUP
a) review and comment upon the contents of this paper;
b) establish the working group as described in paragraph 3.1; and
c) operators, in particular, are asked to validate and prioritize the list of potential new
forecast elements as listed in 2.8.
— END —