WORLD AREA FORECAST SYSTEM (WAFS)
WORKSHOP ON NEW GRIDDED WAFS FORECASTS FOR ICING,
TURBULENCE AND CUMULONIMBUS CLOUDS
ICAO EUR/NAT Regional Office, Paris, France, 14 to 15 September 2009
SUMMARY OF DISCUSSIONS
1. Introduction
1.1.
For a number of years, the World Area Forecast System (WAFS) has provided global gridded
forecasts of elements such as wind direction, wind speed, temperature and humidity. The
ICAO World Area Forecast System Operations Group has requested that the World Area
Forecast Centre (WAFC) Provider States (United Kingdom and United States) develop the
additional capability to provide global gridded forecasts of icing, turbulence and
cumulonimbus clouds.
1.2.
With a view to providing information on the new gridded products and facilitating their
implementation, Conclusion 4/24 of the fourth meeting of the ICAO WAFS Operations Group
meeting (held February 2008) invited the WAFC Provider States, in coordination with ICAO
and the World Meteorological Organisation, to convene a workshop on the use and
visualization of gridded WAFS forecasts of cumulonimbus clouds, icing and turbulence.
1.3.
A two-day WAFS workshop was held at the ICAO EUR/NAT regional office, Paris, 14 to
15 September 2009. The Summary of Discussions from the workshop is presented below.
The workshop was attended by 46 experts representing 13 States, 4 international organisations
(the International Air Transport Association (IATA), the International Federation of Airline
Pilot’s Associations (IFALPA), the International Civil Aviation Organisation (ICAO) and the
World Meteorological Organization (WMO)) and 6 industry representatives (Air France,
COROBOR, IBL Software Engineering, IRAM, Meteo-France International and NetSys
International).
1.4.
Appendix A includes the list of attendees.
1.5.
The objectives of the WAFS workshop were as follows:


To provide information on the new products, their specifications and expected accuracy; and
To provide an opportunity for flight planning companies and workstation suppliers and
software developers to familiarize themselves with and discuss issues related to the automated
products.
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DAY 1: MONDAY 14 SEPTEMBER 2009
2. Background to the requirements
2.1.
Dr Olli Turpeinen, Chief MET/AIM Section, ICAO, and Secretary of the WAFSOPSG,
presented an overview of the decisions that had led to the development of the gridded icing,
turbulence and cumulonimbus (CB) forecasts. Orderly development of the new gridded
forecasts had taken place with consensus reached within the global community through the
WAFSOPSG.
2.2.
The WAFSOPG has recognised that the accuracy and compatibility of the new gridded
forecasts needs to be equal to or better than the traditional (human-generated) significant
weather (SIGWX) forecasts provided today by the two WAFCs (London and Washington).
The visualisation of the gridded forecasts from the WAFCs needs to be simple and similar to
that of the existing SIGWX – i.e. provide the same ease of use. There is expected to be two
types of WAFS output – a complete GRIB2 dataset (for sophisticated flight planning systems)
as well as products in chart form for flight documentation (for pilot’s situational awareness at
the flight briefing stage).
2.3.
Olli briefed the participants at the meeting about new changes in meteorological services that
relate to the NEXTGEN and SESAR projects within the US and Europe respectively, which
will result in major changes to the way air traffic is managed. In fact, the WAFS programme
has been forward looking, where the global gridded fields for icing, turbulence and CB (in
addition to the wind, temperature and humidity data) can be considered as the first step
towards the 4-Dimensional Weather Data Cube concept. The requirement for a single
authoritative source may, in future years, lead to a consolidation in the activities of the
WAFCs
3. Scientific background and content of the new gridded products
3.1.
Bob Lunnon, UK Met Office (WAFC London), summarised the content of the new gridded
products for icing, turbulence and CB, and gave an overview of the collaborative scientific
efforts that have been undertaken by both WAFCs during their development. All of the data
has been provided in GRIB1 code-form for almost 3 years for user trial and evaluation. The
transition to GRIB2 code-form will afford higher temporal and spatial resolutions compared
to GRIB1.
3.2.
Hong Kong Observatory expressed user concerns over the use of the term CAT ‘potential’ as
opposed to CAT ‘probability’. Bob responded by stating that recent changes to the CAT
algorithm have meant that the field could be considered a ‘probability of CAT’. WAFC
London is well aware that the CAT algorithm still over predicts CAT associated with
mountain waves (MTW), and the intent is to address this during the transition to GRIB2.
3.3.
WMO expressed that the three factors that contribute to CAT (namely vertical wind shear,
MTW and convection) have a tendency to interact with each other. Bob agreed that these
factors cannot be treated in isolation. Both centres are using the Ellrod algorithm to predict
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shear induced CAT. New, more sophisticated, algorithms can amplify errors in non-linear,
differentiated, quantities, and so a certain amount of caution is required.
3.4.
IFALPA noted that pilots experience icing in temperatures ranging from PS10 to MS40,
whereas the WAFCs only appear to be considering the zero to MS20 range. Bob recognised
that icing can occur at those quite warm and very cold temperatures; but that NWP prediction
models have errors. These errors are minimised if we (numerically) concentrated attention
between zero and MS20, otherwise there is a tendency for a high false alarm rate (which
operators may not appreciate). A follow-on question to IFALPA clarified that this pilot was
describing Total Air Temperature (TAT) which incorporates compression and is different
from Static Air Temperature (SAT) which is what is given in the NWP models. SAT is the
temperature of the outside air. TAT is the temperature an airplane "feels". The faster an
airplane goes the more friction between the air and the airplane. Friction creates heat. TAT
will always be warmer than SAT. Thus the concern for icing at PS10.
3.5.
NetSys commented that by obtaining the WAFS gridded data from the two WAFCs, there
may be an opportunity for workstation vendors to use the ‘worse case scenario’ from the two
datasets, especially if one is more pessimistic than the other. Bob replied by saying that the
users will notice subtle differences from both WAFCs data, and that verification statistics will
offer users the ability to assess each models characteristics and make informed decisions.
3.6.
NetSys further questioned whether the GRIB2 dataset for CAT will have probability and
severity. Bob replied by outlining that the WAFC models don’t independently predict
probability and severity, although maximum probability may imply severity. Hong Kong
Observatory again questioned what was being provided – probability or potential, and what
thresholds could/should be applied. Also, that significant events needs to be considered in the
verification, rather than trace thresholds which appeared to be presented at the 3rd WAFS
Science Coordination Meeting in April 2009. Bob agreed that there was certainly more
discussion required with respect to verification.
3.7.
IATA expressed that airlines and pilots are concerned with icing occurrence during holding
patterns/phases of flight. Whilst it was noted that the typical holding pattern altitudes (levels)
would be covered by the icing grids, WMO stressed that the WAFS forecasts are for flight
planning purposes – not for the 15-30 minutes duration in a holding pattern, which requires
much higher (finer) resolution data (both in terms of space and time). It would be
inappropriate to use the WAFS forecasts for this. Bob agreed with WMO remarks, but also
noted that aircraft have to have contingent fuel onboard in the event of holding in an icing
layer.
3.8.
Hong Kong Observatory questioned whether False Alarm Ratio had been considered in the
verification in addition to, or as an alternative to, False Alarm Rate. Bob replied that False
Alarm Ratio had not been employed to date as a determiner of the level of skill. Instead, the
WAFCs have tended to use hit rate vs. false alarm rate.
3.9.
WMO drew attention to the cost avoidance of CAT, and that the cost only arises from more
severe CAT encounters. Interpolation by time and space may work for CAT, but may not
work with convective parameter scheme, say. To interpolate between values could be
problematical. IATA outlined that a 15 hour flight, say, will not tend to result in turbulence
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avoidance towards the end of the flight since the operators are aware that the accuracy of the
forecast decreases with time. Bob agreed that it was important to get operators involved in
the discussion.
4. Verification of CB forecasts
4.1.
Bob Lunnon provided an overview of how the verification of CB clouds forecasts (in the
gridded and manual SIGWX forecasts) had been conducted using data from a lightning
detection system. The Sferics system does not have a choice/range of threshold, merely
‘yes/no’ lightning strike. It is feasible that a different scheme will result in different
verification results.
4.2.
The results of recent analyses conducted during November 2008, January 2009 and May-July
2009 had identified seasonal variation and latitudinal variations. The results were very
sensitive to the exact details of the verification scheme employed. WAFC Washington noted
that there had been no changes to the CB algorithm by either WAFC in the period November
2008 to July 2009 to ensure that the statistics could be assess consistently.
4.3.
WMO noted that thresholds for convective rain are used by the model to determine areas of
CB. This was fine. However, Sferics locations do have variability, and therefore a satellite
derived rainfall rate with which to verify the data against may be more suitable. Bob agreed
that there are lots of other tools that could be used, including satellite derived rainfall rates.
4.4.
Hong Kong Observatory wondered whether the WAFCs were considering towering cumulus
(TCU) in the hazards to aviation. While Bob indicated that TCU could be considered, it
needs to be understood that there were no defined requirements to provide this information in
the CB forecast. Annex 3 only makes references for the WAFC to provide CB clouds. This
was further reaffirmed by ICAO remarks that CB had been the only user requirement to arise
from previous WAFSOPSG.
5. Verification of CAT
5.1.
Phil Gill, UK Met Office (WAFC London), presented an objective verification of GRIB and
SIGWX CAT forecasts, where a global verification had been conducted in the period
November 2008 to May 2009. The intention was to demonstrate the quality of the new
gridded forecasts, and to verify the forecasts against GADS (global aircraft data set)
observations.
5.2.
The verification results appeared to show that the (WAFC London) automated CAT field
showed greater skill that the manual (WAFC London) generated CAT forecasts. However, it
was important to stress that the sample size needed to be large enough to provide adequate
verification. The longer range CAT forecasts appeared to show a good degree of consistency,
with little or no drop off in accuracy with lead time.
5.3.
Good skill was evident in the 50-90N latitude band for both WAFCs automated products;
reasonable skill was evident in the 20-50N latitude band for both WAFCs automated
products. For the tropics and southern hemisphere it was difficult to draw any meaningful
conclusions, principally due to the lack of sufficient observations with which to verify against.
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5.4.
Phil continued by outlining that the conversion of CAT gridded forecasts into automated
SIGWX ‘objects’ appeared to offer promising results from initial studies by the UK Met
Office. This may be something for the group to consider for future SIGWX forecasts in chart
form.
5.5.
Canada commented that they were surprised that there appeared little drop off in the accuracy
of the CAT forecasts through time. Phil agreed that he would have expected to see some drop
off; however, this may become more apparent when the new threshold (of DEVG>=4.5m/s) is
used for verification.
5.6.
Hong Kong Observatory remarked that converting the data into objects will have some impact
on performance, and that there is a need for calibration. Phil agreed and noted that much
more work was necessary to determine what the user requirement was, and which was best
(grids vs. objects). IBL pointed out that the current SIGWX uses objects (in BUFR). What,
therefore, will the future automated product be – e.g. 3D data or objects? Bob (Lunnon)
replied that the WAFCs don’t have a definitive answer yet. The working assumption is
gridded data, but this may change based on the discussion with users. IBL outlined that from
the perspective of a visualisation vendor, the gridded data means that descriptions have to be
determined (defined) for each field, whereas objects can have the attributes pre-assigned.
NetSys agreed that it was a matter of convenience; but that the GRIB2 data could be much
more powerful (visually) provided that explicit instructions on visualisation were produced.
The group agreed that this cannot be done in isolation, and it must be conducted in a
structured manner with all interested parties – providers through to users.
5.7.
ICAO outlined that no formal decision on the replacement for manually generated high-level
SIGWX has been taken by the WAFSOPSG thus far, and that users must be convinced that
the new products are operationally acceptable.
6. Verification of WAFS global gridded icing products
6.1.
Jennifer Mahoney, NOAA (WAFC Washington), outlined the motivation behind the
development of global icing fields for aviation, and that it was attributable to fact that icing is
major factor in the flight planning process in terms of fuel loading. The goal of the
verification was to evaluate the quality of the WAFCs global icing across a range of domains
(global and regional).
6.2.
As a representative dataset with which to verify the icing data against, PIREPs were not
considered suitable due to their sparseness and poor sampling across all levels. Instead, the
NOAA team used an icing verification proxy based on satellite derived products.
6.3.
Common findings in the study, conducted November 2008 to January 2009, were that the
WAFC London gridded icing had much greater spatial extent than that of WAFC
Washington, and that the WAFC London product also gave higher ‘potentials’ of icing. In
terms of lead time, the two WAFCs products did not seem to show much change as the lead
time increased (i.e. little drop off).
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6.4.
Overall, the WAFCs icing forecasts tended to provide about the same forecast efficiency, but
the WAFC London product provided lower operational risk.
6.5.
In verifying the manually produced icing forecasts within SIGWX, the automated (gridded)
forecasts from both WAFCs exceeded those prepared manually by the forecasters.
6.6.
Hong Kong Observatory noted that different thresholds had been used (trace, moderate,
severe), and that the WAFC London data had significantly more ‘yes’ forecasts than the
WAFC Washington data. Hong Kong Observatory questioned whether the trace icing was
trying to forecast those areas with no icing, since the WAFC Washington tables suggested that
they forecast more ‘no’ icing events. Sean Madine, NOAA, agreed with the remark, and
commented that the choice of trace in the CLIP threshold had been ‘tuned’ so that it led to a
more meaningful comparison. Sean also noted that with respect to bias, the WAFC London
data showed greater icing extent in the horizontal and vertical (i.e. greater volume), thus
larger areas, and thus larger ‘potential’.
6.7.
Germany commented that some slides had shown maximum icing potential, others maximum
icing intensity. Sean responded that there are two icing attributes – mean and maximum icing
in a layer. Intensity could be considered synonymous with ‘potential’ (with values 0 to +1).
Bob Lunnon commented that when considering icing ‘potential’ (range 0 to +1), values in the
order of >=0.5 has been shown to reflect severe icing when based on validation with PIREPs.
6.8.
Germany questioned whether high potential can imply high severity. Sean commented that,
in his opinion, there is a correlation between a potential and intensity.
7. Observations on WAFS gridded forecasts
7.1.
CM Shun, Hong Kong Observatory, presented a comparison of the trial gridded forecasts
available from both WAFCs, and noted that there were a number of compatibility and quality
issues that still need to be addressed.
7.2.
In respect of compatibility between the two WAFCs, CM noted that the WAFC London CB
field was more extensive in the horizontal and vertical compared with the WAFC Washington
CB field. With regards to mean in-cloud turbulence, the WAFCs produced data in similar
ranges. For maximum icing potential, there appeared significant differences in spatial
coverage in the tropics and at high latitudes. With respect to maximum CAT, the WAFC
London field appeared less extensive generally.
7.3.
CM continued by outlining some quality issues. For example, in the mean in-cloud
turbulence field at FL180, during winter and summer months, large values were present in the
WAFC London data at high latitudes in both hemispheres, which were not evident in the
WAFC Washington data. Some common issues have been identified and there is a need to
conduct verification for all seasons and examine model climatological biases. There also
appeared to be a need to consider CB diurnal variation.
7.4.
In terms of the verification conducted, CM noted that systematic verification of in-cloud
turbulence was yet to be conducted. For icing, verification based on another icing product for
ground truth could be considered. For CAT, verification appeared to be based on DEVG
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>=2m/s rather than the ICAO adopted turbulence metrics. For CB, verification had been
based on Sferics data rather than observations of CB.
7.5.
CM stressed the need that thresholds for verifying and visualising the gridded forecasts need
to be determined in consultation with the users. Hong Kong Observatory had conducted a
preliminary survey of users, and obtained a range of opinions from pilots, airlines,
dispatchers, etc. The findings of the HKO survey suggested that users had concerns with
regards compatibility (between the two WAFCs datasets), quality, verification and calibration.
Users would expect to see such matters addressed (e.g. systematic verification) before the
products could be deemed suitable for operational use. In terms of the suitability of the
WAFS gridded forecasts for icing, turbulence and CB clouds as a replacement for current
SIGWX, CM noted that there were visualisation issues (e.g. high at a glance), as well as the
need to include significant weather information such as tropical cyclones, volcanic ash,
sand/dust storms etc on the products.
7.6.
Bob Lunnon suggested that Hong Kong Observatory be invited, officially, to be a partner in
the verification process, to address the issues raised. In addition, Bob commented that there is
still much work to be done to convince users that the products will be fit for operational use.
CM responded that they would be happy to engage in a verification dialogue with the two
WAFCs. It needs to be demonstrated that the introduction of the new forecasts meet the
operational service needs of the operators and also not be misleading in the context of flight
planning.
7.7.
WMO commented that there is a real issue of how people have been brought up to use today’s
WAFC products – for example, weather in terms of phenomenon such as the passage of a cold
front, activity of a tropical cyclone, etc. Pixels on a chart/screen will not be interpreted
adequately. Users need to react rationally. The modellers in the UK and US are doing what
they can to improve the forecasts, but we need to address the user’s interpretation of the
forecasts.
7.8.
Canada expressed that the gridded data is perfect for ingestion into automated flight planning
systems. Decisions will be based on temporal and spatial resolutions that are not currently
available to these users. WMO agreed, but noted that there is a need to give them [pilots] a
product that they can understand quickly and easily, thus convincing the pilot that the
optimum flight track generated by their flight planning system is the best route.
7.9.
CM commented that the use of ‘objects’ versus ‘gridded data’ is something to be determined
in other fields, not just WAFS (e.g. new terminal forecast). The two products, graphical and
gridded, must be consistent. As present, the gridded outputs of the two WAFCs do not appear
to be consistent.
7.10.
IATA questioned whether it was premature for Hong Kong Observatory to be surveying users
on the outputs of the gridded data given that the products are only experimental at this time.
CM responded by noting that the timing of the survey was in view of the intention to
introduce the fields for icing, turbulence and CB clouds into Amendment 75 to Annex 3
(applicable November 2010), and that the replacement for SIGWX could be just three years
later (Amendment 76). Therefore, Hong Kong Observatory did not feel that the survey had
been premature. IFALPA commented that their response to the HKO survey has come from a
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representative with good knowledge of the development of the products. In addition,
IFALPA recognise that there are many issues regarding the training of pilots etc.
7.11.
In response to CM’s comments about the intentions of Amendment 75 to Annex 3, WAFC
Washington noted that the Annex 3 provision will only introduce the new gridded forecasts as
experimental products – i.e. they are not to be used operationally as of November 2010. In
terms of training, such matters should be addressed through the WAFSOPSG where there is
both IATA and IFALPA representation. There is clearly the responsibility of airlines to
ensure that their flight crews are adequately trained in the use and interpretation of the new
forecasts.
7.12.
NetSys questioned ‘value added’ products, and noted that the new data can add value.
However, this may be determined by whether the WAFCs intend to dispatch the data as
SIGWX ‘object’ over the WAFS broadcasts. If objects are not generated, there is a clear need
to pin-down the parameter thresholds so that standardised visualisation can be achieved.
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DAY 2: TUESDAY 15 SEPTEMBER 2009
8. Opening remarks
8.1.
WAFC London provided the workshop with a statement, on behalf of the two WAFCs, of the
development of the gridded forecasts over the past 4 years, in response to the stated
requirements of IATA for global gridded fields for icing, turbulence and CB clouds. WAFC
London noted that such developments are at the forefront of where model capabilities are
today, and it was recognised (by the WAFCs and others) that there are both positives and
negatives to be taken from the status of the products as they are today.
8.2.
WAFC London continued by stating that challenges lie ahead for the MET community, not
least with developments such as NEXTGEN and SESAR, where global gridded forecasts data
will be ingested into future ATM systems without human intervention.
8.3.
In light of the presentations during day one of the workshop, and noting the discussions that
followed, it was worthwhile highlighting that there has been considerable effort undertaken by
the two WAFCs, and additionally Hong Kong Observatory, with regards to validating the
consistency and compatibility of the gridded datasets. Clearly, more work is to be done,
which is why the WAFCs and others recognise that the gridded forecasts for icing, turbulence
and CB clouds should only be available in an experimental form at the present time.
8.4.
With regards to training, the WAFCs are keen to work with States to disseminate information.
In respect of the consistency of the gridded fields between the two WAFCs, there is still work
to be done, but it is worthwhile noting that given that the forecasts are based on independent
global models. The output of these models will result in some divergence and it would not be
expected that output would be 100%. The question is what is acceptable is the challenge.
8.5.
Today, there needs to be visualisation considerations to bridge the gap between the current
(manually produced) SIGWX charts and the future gridded forecasts. It was recognised that
visualization is very complex and involves processes that requir more work.
8.6.
WAFC London closed their remarks by stating that there is a need for the workshop to
consider the requirements, where input from all concerned is vital. Consensus has to be
reached between what will be of use to vendors, pilots, airlines, etc.
9. Visualisation aspects of GRIB
9.1.
Lauren Reid, UK Met Office (WAFC London), highlighted the stated requirement of
WAFSOPSG/4 for high-at-a-glance SIGWX products, targeted especially at the Least
Developed Countries, as well as the intended web-based distribution.
9.2.
High-glance SIGWX (HG-SIGWX), as well as single field visualisation, would be capable of
displaying MET fields based on the gridded data for T+6 to 36 timeframes at 3-hourly
intervals, for all ICAO standard areas.
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9.3.
IFALPA commented that the HG-SIGWX examples shown by Lauren had, perhaps, too much
content, since pilots will typically have just 5-10 minutes to assimilate MET information at
the flight briefing stage.
9.4.
WAFC Washington noted that the quality of the products and the consistency between the
two WAFCs data has to be, and will be, addressed. In light of this, WAFC Washington posed
the following questions to the IATA and IFALPA representatives present: How does flight
planning really work, especially for the short-haul versus long-haul community? What
options do the flight planners have, and how do they interact with flight dispatch? It appeared
that SIGWX charts based on the gridded data should be provided as supplemental information
to provide quick situational awareness. Thus, what is the operational service needs?
9.5.
IATA responded that we (as a MET community) need to consider where we are headed – i.e.
NEXTGEN and SESAR. There is a need to ingest the data to prepare better routes – i.e.
optimised flight tracks. In addition, there is also a need to reproduce such data in graphical
form for the quick assimilation outlined by IFALPA a moment earlier – both assimilation of
SIGWX in the horizontal and vertical. Airline operators all have different operational needs,
some of which may be enforced by Regulators. ATM, flight planning and the pilot
communities must be receiving the same, consistent, information, and therefore there is a
requirement for products that offer quick situation awareness.
9.6.
IFALPA commented that short-medium haul traffic routes are fairly static, dictated by air
corridors/sectors. For the long-haul operators, routes can change constantly whilst en-route,
taking into consideration the current weather situation and air traffic control demands. Pilots
need to know when they can expect to enter a turbulent area, where are the jetstreams, etc.
Pilots have limited time to consider MET as well as aircraft loading, passengers, etc.
IFALPA noted that the forecasting of jets is typically very good on the current SIGWX charts;
however the main problem was the forecasting of CB.
9.7.
WAFC Washington remarked that the quality of the current SIGWX forecasts is considered to
be generally good amongst users, but it was accepted that there are deficiencies even on the
timescales of today’s SIGWX products. Change will be a huge adjustment for all – providers
and users of the MET data.
9.8.
WMO commented that there is clearly variation in how the operators optimise their flight
plans, which is why the verification of the gridded forecasts is so important. The achievable
reliability of CB forecasting is much lower than it is, say, for a field such as upper wind.
Therefore, operators will need to know what the expected error will be in CB, jetstream, CAT
forecasts etc. With this information, operators will be able to apply a cost (weighting)
function – for example, how much will it cost an airline to avoid or fly through an area of
CB? Therefore, it was important to intensify the dialogue between ATM, pilots, dispatch, etc.
The relative accuracy of each forecast element, through verification, will be very important to
the flight planning industry – for example, seasonal variation, latitudinal variation, etc.
9.9.
IATA noted that is was important to understand the limitations. ‘Free flight’ across part of
the world such as the Pacific and Indian Oceans has led to a change in thinking for the pilot,
as well as a change in the flight planning algorithms. Flight tracks continually change based
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on SIGMET information, updated wind information, etc.
operators and pilots to get the full MET picture.
9.10.
It was important for airline
NetSys commented that the gridded data was excellent for flight planning, but that there was a
need to separate out the considerations for visualised products. Colour palettes, for instance,
do not always help if one operator uses a different colour palette to another operators. In
addition, most LDCs around the world still do not have colour printing capability (principally
due to the costs of replacing ink cartridges on a regular basis). Therefore, there is a need to
decouple the model data (grids) and the viewing capabilities (charts).
10. Visualisation of gridded forecasts
10.1.
CM Shun, Hong Kong Observatory, presented the workshop with a range of possible
solutions for visualising the gridded WAFS data, including concatenated charts, horizontal
strip charts and vertical cross-sections. Such products could be tailored to the specific
requirements of the user – for example, planned route, colour scaling, etc.
10.2.
CM continued by expressing that there was a need, based on their feedback from operators,
for safety related information to be retained on the SIGWX charts of the future – for example,
information related to tropical cyclone, volcanic ash, etc.
10.3.
WAFC Washington stated that, as noted earlier by IATA, each airline will have their own
(unique) requirements. The requirements placed upon the WAFCs are clearly stated in Annex
3. But, are the WAFCs going to be expected to compete with private sector industry to
produce such visualised products? The products provided by workstation visualisation
vendors should be viewed as supplemental information based on the business plans of the
operators. It is not for the WAFCs to end up being in direct competition with such vendors.
10.4.
CM noted these constructive remarks, but expressed that there was a need to consider future
model charts – such as horizontal strip charts, vertical cross-sections. What will today’s
SIGWX charts be replaced with tomorrow? It was important, therefore, to engage
workstation vendors at an early stage, in order to determine some ‘standard products’.
10.5.
Canada commented that the visualisation ideas posed by HKO should not be viewed as the
outputs of the WAFCs. Today’s SIGWX will be superseded by a product of tomorrow, and
the ideas presented certainly appear to be a step in the right direction.
10.6.
WAFC London expressed that it could be easy to get carried away. There needs to be defined
a basic capability and requirement. Strip charts, vertical cross-sections, etc are at risk of
being too advanced for users at this time. In addition, the MET community cannot ignore
NEXTGEN and SESAR, where we are talking about data not products.
10.7.
The Ukraine representative commented that the visualisation ideas presented by HKO were
good examples. Within the ATM community there is a distinct lack of ‘awareness’ of MET.
It was important, therefore, to consider better ways of providing situational awareness.
10.8.
South Africa suggested that there is a need to reflect safety related information on the
products, as mentioned earlier by HKO. The current visualisation ideas are a good starting
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point with which to move forwards with, and there needs to be closer collaboration between
the WAFSOPSG and user communities.
10.9.
WAFC Washington agreed that there was a need to define the role and responsibility of the
WAFCs. It was important that the WAFCs don’t cross boundaries. The US will be
conducting a safety risk assessment of the new gridded products, and it would be expected
that other States will need to follow suit before the products are introduced operationally.
11. Workstation vendor presentations
Corobor (France)
11.1.
Alexandre Gluckman, Corobor, presented a series of visualisation ideas for the workshop to
consider based on their MESSIR-AERO platform. The gridded data has the flexibility to be
displayed as single layer fields or as multi-layers.
11.2.
WMO noted that the presentation had used terms such as ‘potential’, ‘probability’ and ‘risk’,
and that risk comes as a product of probability and severity. Alexandre responded to the
observation, and commented that the term ‘risk’ may have been an incorrect interpretation in
the presentation.
IRAM (Russian Federation)
11.3.
Tatiana Bazlova, IRAM, presented a range of visualisation ideas based on their MeteoExpert
platform. Tatiana noted that the new gridded products offer significantly greater detail
compared to today’s SIGWX. There could be a range of products visualised, colour scaled
etc, and it was important for the thresholds to be determined so that users could interpret the
data in a consistent manner.
11.4.
Tatiana expressed that a ‘hazard contours’ concept could be adopted to provide simple and
informative situational awareness.
12. ADWICE
12.1.
Sonja Jirsch, Deutscher Wetterdienst (DWD), presented a brief overview of DWD’s icing
prediction system called ADWICE. ADWICE produces two outputs – namely an icing
scenario (freezing, convective, stratiform or general) and an icing intensity (light, moderate or
severe).
12.2.
The intention of the ADWICE project is to provide the (experimental) icing products to the
pilot community in the near future, as well as expand consideration to the global domain –
although noting that the Annex 3 requirement of the WAFCs will be to provide global icing
forecasts. Sonja questioned whether, by providing such products from a National Met Service
(NMSs), there would be any conflict with the products provided from the WAFCs? WAFC
London responded that the role of the WAFCs was to provide global gridded data for flight
planning; therefore, for NMSs to prepare their own tailored icing products, there shouldn’t be
any conflict. WAFC London noted initiatives such as FlySAFE in this regard.
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13. Further workstation vendor presentation
IBL Software Engineering
13.1.
Jozef Matula, IBL Software Engineering, presented findings from experiments using the new
gridded data, and noted that the long-haul concatenated SIGWX forecast charts had been the
first stage in considering alternative visualisation ideas for SIGWX data.
13.2.
Jozef commented that the proposed gridded data cannot be reasonably presented in the
geospatial context, and that adding vertical extent can lead to too much information being
available in a layered view. Considering the opposite extreme, with a simple/minimalist
approach, visualisation can cope better with vertical extent (as per current SIGWX) but can
lead to loss of specific detail. Even cross-section visualisation, whilst being easy to interpret,
can hide/mask surrounding information.
13.3.
Jozef invited the workshop to consider whether the gridded data could be converted into
SIGWX ‘objects’, in much the same way that today’s SIGWX data is presented as objects in
BUFR code form.
13.4.
WAFC London thanked IBL and the other workstation vendors for the presentation of their
visualisation ideas, and questioned how time consuming it was to generate, for example, a
route-specific en-route cross-section. IBL commented that it was not a great problem for
most vendors considering today’s computational power. Interpolation of data can be done in
several ways however, and this may be more of an issue.
13.5.
IFALPA commented that providing just a route-specific cross-section to a pilot may be
insufficient, in particular when considering the potential for in-flight re-routing. Therefore,
IFALPA believes that there is a need to retain a ‘plan’ or ‘global’ view chart, especially for
twin-engine operations. IBL responded that the generation of SIGWX objects based on the
gridded data could be one way of meeting this requirement. WAFC London remarked that we
must not lose sight of the fact that, in future, the pilots will have an electronic flight bag, and
that these will assist in situations of en-route re-direction since the pilot will be able to
generate new cross-sections, say, whilst in flight.
14. Flight planning operations
14.1.
Hans-Rudi Sonnabend, Lufthansa Systems Aeronautics, presented an overview of how they
use the WAFS data for flight planning – paying due consideration to flight safety, passenger
comfort, environmental impact (i.e. reduced CO2 emissions), cost, etc. The current WAFS
forecasts are used in two ways by the airline industry. The upper-air gridded data is ingested
into the flight plans for fuel calculations; whilst the BUFR SIGWX data is used for dispatch
information and flight crew briefing.
14.2.
Horizontal and vertical forward optimisation software is used to generate minimum fuel
tracks, minimum time tracks, minimum cost tracks, minimum distance tracks, fixed or user
defined tracks, and free flight tracks.
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14.3.
During the last 2 years, Lufthansa was involved in a hi-resolution gridded data trial with
WAFC London, the results of which led to the recommendations for the new gridded WAFS
data to be presented on a regular 1.25 degree grid (unthinned), 3-hourly time intervals, and
additional flight level data between FL240 and FL400.
14.4.
NetSys questioned whether Lufthansa verifies the optimisation suite. Hans-Rudi responded
by outlining that statistical comparison is conducted, and that generally the errors were ±2
minutes flight time and ±200kg fuel load.
14.5.
Canada asked how much the icing, turbulence and CB cloud forecasts could improve the
situation. Hans-Rudi outlined that improvements will be achieved – for example, more
accurate information about icing/no-icing areas will reduce the fuel penalties that airlines
currently have to carry.
15. Breakout sessions
15.1.
During the afternoon session, participants split into two groups – the MET service provider
community and the user (industry) community – to conduct breakout sessions. The WAFCs
did not participate in the breakout sessions so as to not influence either group. Each breakout
group was tasked to consider a number of questions posed by the WAFCs and report back
their findings to the workshop.
15.2.
Feedback from the user community demonstrated that an integrated hazard contour plot
(chart) could be of value provided that it retained all of the objects as seen on today’s SIGWX
charts (i.e. jetstreams, CAT, CB etc). The users noted that there was a need for consistent
methodology when using colours to depict SIGWX elements and that graphical products
would need to have monochromatic alternatives. Users commented that they were happy with
what they receive today, and that there was a need for equivalent products (based on the
gridded data) in future years. It was also expressed by pilots that fronts should be reinstated
on the SIGWX if at all possible, to facilitate situational awareness. The users noted that the
sheer quantity of information available could be a concern, since it would lead, say, to an
increase in the number of SIGWX charts to assimilate. However, the generation of
concatenated charts could be of value. The users noted that probabilistic forecasts was,
perhaps, something for the future since they could be of value in the flight planning and
decision making process.
15.3.
Feedback from the MET service provider community identified that there was clearly a need
for two types of product to be produced – namely gridded data and chart visualisation. It was
recognised that there needs to be clear standards established regarding what is being
represented – i.e. potential, probability, etc. In respect of the quality of the data, the
verification process should lead to reliable, repeatable and predictable information. The role
of the MET service providers will be to add-value to the baseline forecast. As stated earlier,
airlines have different business requirements, and the value-added products could be tailored
to their (unique) operating requirements (e.g. concatenated charts for long-haul). It was also
recognised that there would be a need for SIGWX objects to be provided during the transition
from today’s manually produces SIGWX to tomorrows NEXTGEN and SESAR concepts.
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15.4.
The WAFC Provider States responded to the feedback, and noted that there were a number of
similarities in the findings of the two breakout groups. A number of aspects appeared to come
out the discussions over the course of the two-day workshop, including the clear requirements
for an automated product for ingestion into flight planning systems (i.e. global grids) and a
product similar to today’s SIGWX (based on the gridded data) to provide situational
awareness at the flight briefing stage. There appeared to be a lack of a requirement for single
field charts for LDC members. The need to develop ‘object’ orientated plots based on the
gridded data was expressed (akin to today’s SIGWX charts), and sophisticated visualisation
should be left to the vendors. There was a need to consider the representation and format of
the objects. The WAFCs also took note of the remarks from the pilot community for fronts to
be reinstated, where possible.
15.5.
WMO commented that there appeared to be a strong trend towards industry standards such as
XML, GML, etc, rather than proprietary code forms such as the WMO BUFR code form.
France agreed, but noted that the standard was not yet mature for SIGWX data in a
XML/GML form; therefore, it may be wise to consider utilising BUFR in the near term.
NetSys remarked that from a workstation visualisation perspective, there was unlikely to be
any issues if BUFR was used to represent the SIGWX ‘objects’ discussed earlier. IBL agreed,
but noted that any changes to BUFR would necessitate changes to the encoder and all enduser decoder suites. Therefore, the longer term goal should be XML, say, which is extensible
and would result in fewer end-user upgrades when changes are made.
16. Closing remarks
16.1.
The workshop facilitator and ICAO Secretariat gave closing remarks, and thanked everyone
for their active participation during the two-day session. The summary of discussions from
the two-day workshop and the powerpoint presentations would be posted on the WAFSOPSG
website
in
due
course
(via
URL:
http://www2.icao.int/en/anb/metaim/met/wafsopsg/Pages/default.aspx). The workshop closed at 1700 hours on Tuesday
15 September 2009.
15
APPENDIX A
LIST OF PARTICIPANTS
AUSTRALIA
Neville KOOP
BRAZIL
Fernando BRANDAO
CANADA
Ken MacDONALD
CHINA
C.M. SHUN
GERMANY
Sonja JIRSCH
Reinhard WERNER
FRANCE
Patrick JOSSE
JAPAN
Yasuhiro
MATSUSHITA
OMAN
Ahmed HAMOUD
RUSSIAN
FEDERATION
Yuliya NARYSHKINA
Eleonora
PAKHOMOVA
SOUTH AFRICA
Gaborekwe Esther
KHAMBULE
UKRAINE
Yuri V. SADYCHKO
NETSYS
INTERNATIONAL
Tiaan WESSELS
IATA
Graham RENNIE
Hans-Rudi
SONNABEND
Ndiwa WACHINA
IFALPA
Jean-Félix BARRAL
Carole COUCHMAN
WMO
ICAO
Herbert PUEMPEL
Greg BROCK
Raul ROMERO
Olli TURPEINEN
UNITED KINGDOM
Nigel GAIT
Philip GILL
Ian LISK
Bob LUNNON
Lauren REID
Chris TYSON
Andy WELLS
UNITED STATES
Steven ALBERSHEIM
Larry BURCH
Michael GRAF
Robert HELGESON
Sean MADINE
Jennifer MAHONEY
Bob MAXSON
Michael Pat MURPHY
AIR FRANCE
Marcus FARRELL
COROBOR
Alexandre
GLUCKMAN
Erick NUWENDAM
IBL SOFTWARE
ENGINEERING
Herbert LEPPER
Jozef MATULA
IRAM
Tatiana BAZLOVA
Nikolay
BOCHARNIKOV
METEO FRANCE
INT'L
Peng Lim LY
— END —
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