WORLD METEOROLOGICAL ORGANIZATIONCOMMISSION FOR ATMOSPHERIC SCIENCES
THORPEX ICSCGIFS TIGGE Working Group
Eleventh Meeting
Met Office, Exeter, UK
12-14 June 2013

CAS/THORPEX ICSC/
GIFS-TIGGE 11
Report of the meeting__________

Original: ENGLISHREPORT OF THE MEETING

1. Organisation of the meeting
1.1. Aims of the meeting
Dale Barker welcomed members to the meeting on behalf of the Met Office. He
noted that post-THORPEX arrangements are a major topic for debate and the threeprojects S2S, PPP and HIW all have relevance to this Working Group. It was notedthat data assimilation and ensemble prediction work very closely together in the Met
Office. Also important was a possible restructuring of the WWRP WGs and theformation of new groups. The Open Science Conference (OSC) coming up in 2014
was an important event to which the group should contribute and the purpose andgoals need to be kept in mind.
Gilbert Brunet also welcomed the members to the Met Office. He is on secondmentfrom Environment Canada and is currently Director of Weather Science in the Met
Office and chair of the WWRP JSC. He outlined the objectives of the WWRP i.e.,advancing the science of weather prediction and especially the role of bringing
people together from developing countries and engaging young scientists. He briefly
outlined the 2009- 2017 WWRP Strategic Plan. Noting that THORPEX will end in2014 he noted some probable changes to the WG structure and the formation of
new projects i.e. S2S, PPP and HIW. Regarding PPP he wished to see moreengagement from the Southern Hemisphere community and that a number of topics
should be tackled in conjunction with the WCRP. Finally he said that a main themeof the OSC in 2014 would be seamless prediction on timescales from minutes tomonths.
Richard Swinbank then outlined the aims of the meeting which included reviewing
and consolidating current work, collaboration with the SWFDPs, participation ofsome TIGGE partners in GEOWOW and discussing TIGGE-LAM development. A
main purpose of the meeting was also to look forward and consider issues such ascontinuation of the TIGGE archive and how best to support the S2S, PPP and HIW
projects. In addition there was the need to discuss the formation of a proposed newgroup on Predictability, Dynamics and Ensemble Forecasting.

CAS/THORPEX ICSC GIFS-TIGGE-11/Report p. 2
1.2 Adoption of the agenda
The agenda was discussed and agreed.
1.3 Working arrangements
The working arrangements were agreed. All presentations will be displayed on the
THORPEX website.
2. Report and actions from previous meetings
2.1. Status of actions from the tenth GIFS-TIGGE meeting (R. Swinbank)
The actions were reviewed:
P1 – ECMWF, NCAR statistics were available [post meeting note: CMA data havenow been included].
P2 – Work is continuing.
P3 – ongoing, updating is needed by several data providers
P4 – completed
9.3.4 – a link has been added to Mio Matsueda’s tools – this action will bereclassified as permanent (P5)
9.4.1 – completed
10.3.1 – completed
10.3.2 – some discussions had taken place. This topic will be taken forward as a
new action.
10.4.1 – completed – also on the agenda
10.5.1 – completed.
10.5.2 – completed – a proposal has been developed.
10.6.1 – completed – contact has been established.
10.6.3 – encouragement was provided but the action was not implemented. Will be
retained as a new action from this meeting.
10.6.4 – ongoing, will be revised and retained as an action from this meeting
10.7.1 – not much progress to date; ongoing. [Tiziana Pacagnella is likely to be
invited to. an upcoming Workshop on La Plata Basin Project.].
10.7.2 – completed – but not much use of the TIGGE data can be made.
10.8.1 – completed
10.9.1 – completed
10.10.1- completed
10.11.1- completed
2.2 IPO update and post –THORPEX plans (T. Nakazawa)
The main actions for the GIFS-TIGGE WG arising from ICSC10 were outlined. ForICSC 10(7) the action was ongoing and some progress was being made and the
ICSC 10(8) topic was on the agenda and significant progress was being made.
The recent programme of meetings of the THORPEX Working Groups and projects
was then described. Some other main actions from ICSC 10 were described
including the preparation of a comprehensive review paper on the whole THORPEX
programme, participation in DACA 13 and the planned HIW project.
The current and proposed new structure of the WWRP was then outlined. The new
structure would comprise time limited projects (funded by Trust Funds) supported byWorking Groups or Expert Teams funded by the WMO Core Budget. This included
the proposed merger of the PDP and GIFS-TIGGE WGs. This would be discussed
further at the ICSC 11 and JSC 6 meetings planned for July 2013. The

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recommendations would then be put to CAS in November 2013 and finally adecision taken to introduce the structure by EC 66 in June 2014.
2.3 Outcome of THORPEX ICSC-10 and EC 64/65 meetings (T. Nakazawa)
EC 64 approved the S2S project in June 2012. A Trust Fund was established inAugust 2012 and offers to host the International Coordination Office (ICO) werereceived from Korea and Bhutan. Following clarification Bhutan withdrew, and so the
ICO will be hosted by Korea.
EC64 also approved the PPP project and again a Trust Fund was set up in August
2012. Some offers to host the ICO have been received but no final decision has yet
been taken [post meeting note: the ICO will be hosted by Germany].
ICSC 10 requested that a third legacy project, on high-impact weather (HIW), shouldbe created. A Workshop was held in Karlsruhe in March 2013 and a Task Force has
been set up under the leadership of Prof. Sarah Jones to prepare a draft
Implementation Plan for consideration at ICSC 11.
During discussion it was recognised that the projects and new WG structure would
need to work closely together. In essence a matrix structure is being proposed.
There would probably need to be reciprocal representation from the WGs on the
projects and vice versa with the WGs tackling topics of importance to the projects.

3. TIGGE archive
3.1. Brief updates from the archive centres (reps from archive centres)
NCAR: There is a gradual winding down of activity towards the end of the 2014
cessation of TIGGE archiving and NCEP data reprocessing at NCAR. No further
changes are being made so the operation is in “frozen mode”. There is a willingness
to help in transiting NCEP data direct to ECMWF rather than via NCAR. The
validation portal will continue as will CXML archiving.
ECMWF: Data collection is generally fine with the exception of CPTEC. This data
often has gaps and ECMWF has difficulty getting a response from the contact
person. There also some gaps in NCEP data, the Sunday data is occasionallyabsent. Again there is difficulty in maintaining close and effective contact. Effective
technical contact points are needed to resolve problems. Thanks were expressed to
all the data suppliers for continuing to provide the TIGGE data.
Parallel archiving of European TIGGE-LAM data has been commenced under the
GEOWOW programme. At present 2 EPSs are included although this will increasein future. Work on extraction of time series data will start soon and will be completed
before August 2014.
ECMWF again stated that it is their firm intention to continue archiving TIGGE data
after the end of the THORPEX programme and the data centres are strongly
encouraged to continue to supply the data sets.
Action 11.3.1: Yuejian Zhu to inform ECMWF of the name of technical contacts at
NCEP and NCDC to liaise over the practicalities of providing the NCEP data to the
ECMWF archive centre, by end of July 2013. [post meeting note: POC of NCEP and
NCDC has been offered via email]CAS/THORPEX ICSC GIFS-TIGGE-11/Report p. 4
Action 11.3.2: The working group requests Christopher Cunningham and Yuejian
Zhu to ensure that missing data from CPTEC and NCEP is minimised by liaisingwith contact points to respond to requests from archive centres to fill any gaps.

CMA: Progress on the TIGGE archives was reviewed. About 750 TB of data was
now in the archive. Around 60% of this was ECMWF. Although some aspects of thearchive were updated in 2013 there is still reliance on manual tape loading.
Automated loading will not be available for another 2 years. Generally upgrading thefacility in the future is going to be a real challenge. Also, as resolution of the models
increases so demands on the archive increase. CMA has already spent more than
£0.3m on improvements and 2-3 people are needed to maintain the archive. Someway to limit the increase in data needs to be found. In addition CMA has found that
only about 10% of the data in the archive is used for research purposes.
A first assessment report on the future of archiving TIGGE data has been prepared
but this is inconclusive and no final decision has been taken by CMA management.
Further discussions are now taking place recognising the need to balance future
investment and benefits.
Action 11.3.3: Archive centres are requested to investigate which types of TIGGE
data are most widely used.

3.2 Brief news from the data providers, (reps from data providers)
ECMWF: There has been little change since the last meeting. The re-forecast data
set has been extended. The ensemble system (now known as ENS) is unchanged
from June 2012. The high resolution forecast model will be changed in a few weeks
time to 137 levels and later in the year the ENS will be increased to 91 levels. The
ENS will couple to the ocean from day 1 rather day 10.
Canada: The system was changed on Feb. 13 2013 to V3.00. The analysis is now
at 66km (previously 100km) and has 74 levels. More observations are assimilated –especially from AMSU. A bias correction is added to input data and the time stephas been reduced from 30 to 20 mins. There is also improved physics and filteredtopography. This has resulted in a big improvement to the surface fields. There areplans to increase the resolution to 50km in 2014 and further improve the EPS
system.
JMA: JMA is the lead centre under CBS for EPS verification and provides acomparison of EPS verification results. The forecast range has been extended from
9 to 11 days. In March 2014 it is planned to increase the resolution to about 40km
and the frequency to twice per day, while reducing the ensemble size to 27
members. Gridded data to the TIGGE archive will not change. JMA recommends
some common (fixed) resolution to middle and upper atmosphere data to control
data volumes in the future.
Action 11.3.4: JMA and CMA are requested to consider extending CXML tropical
cyclone forecast data to all ocean basins.

CAS/THORPEX ICSC GIFS-TIGGE-11/Report p. 5
NCEP: The horizontal resolution of the model has been improved to around 5055km. As a result hurricane forecasts were improved with a 10-20% improvement intrack prediction. Initial condition improvements were responsible for another 5%
improvement. The global EPS operates at 50km resolution out to 8 days and thenat 70km out to 15 days. It is run 4 days each day with 20 members. Next year aunified EPS at 33km and 64 levels will be introduced. But resources are limited toincrease ensemble membership, and NAEFS (combined NCEP and CMC) shouldhave reasonable ensemble size. In 2016/7 a ten fold increase in computing power isplanned and there are ambitious plans for coupled system at 15-17km resolution out
to 10 days and then 35 km out to 32 days.
NAEFS was showing good promise with a gain of 1 day from the combined
ensemble. However, a lot of works had been devoted to setting this up operationallyalthough this is now regarded as justified. Bandwidth is an issue and priority forcoming NAEFS half-degree data exchange in real-time.
Met Office: The 2012 upgrades to MOGREPS were outlined. A 2.2km UK ensemble
with predictions to 36h is nested in a 33km global ensemble with predictions out to72h. The North Atlantic / European regional model will cease. There are now 4
cycles each day with 12 members. The ETKF now uses 44 perturbed members.
MOGREPS-15 (which is used for TIGGE) still runs 24 forecast members. The grid
length is still 60km but the model now uses 85 levels.
A new dynamical core (ENDGame) is planned plus associated physics changes. It is
proposed to extend the 33km short-range global ensemble from 3 days to longer
range, which would support the Global Hazard Map presentation and provide global
probabilistic products to complement the deterministic forecast out to 6 days. There
will also be a suite of medium range and monthly/seasonal forecasts, using acoupled ocean-atmosphere ensemble.
KMA: The KMA EPS system development was outlined. As of June 2013 a hybrid
ensemble/4dVar prediction system is in place. And a seamless prediction systemfrom the medium range to sub-seasonal (3-4 weeks) will be developed by the end of
this year. The model will be coupled to the ocean model. A convective scale EPS isbeing developed to provide short range probabilities of HIW over local areas. On theDA side the Hybrid Ensemble 4D-VAR is being further optimised. The global EPS
will be at 20km resolution in accordance with new high performance computing
resources.
CMA: An update of EPS plans was provided. GRAPES GEPS will provide 30
member global forecasts at 25-50 km resolution.
BOM: AGREPS (Access Global and Regional EPS) will operate to 10 days globally(at 60km and 70 levels) and 3 days regionally. The model is running daily but has
not been declared operational, so the forecasts are not yet being added to the
TIGGE database. Timeframe for system to be operational is still undecided.
CPTEC: A new global DA system has been introduced: the Gridpoint Statistical
Interpolation (GSI) analysis scheme at T299L64 global resolution. This resulted in
substantial improvements in forecast skill, especially in the tropics. A new improved
EPS, which includes better perturbations and bias corrections, is being implemented
operationally. There is a plan to move to perturb their own analysis rather than use
the NCEP analysis.

CAS/THORPEX ICSC GIFS-TIGGE-11/Report p. 6

Meteo-France: The global EPS is still based on singular vectors. It has 35 members
on a stretched grid and is run at 6 and 18 UTC. A re-forecast system is being built. A
new computer system is expected in about 2 years’ time. A 2.5 km model EPS isplanned based on the AROME system. Data will be submitted to TIGGE-LAM.

3.3 Continuation of the TIGGE archive after 2014 (R.Swinbank and M. Kyouda)
ICSC 10 invited the GIFS-TIGGE WG to consider this matter in some detail andreport to ICSC 11 (see Action ICSC 10 (8)). The previous meeting concluded that atleast one archive centre was needed. ECMWF has offered to continue to archive
data after 2014 but a solution needs to be found so that the NCEP data cancontinue to be provided. NCAR will stop TIGGE archiving activities but the validation
portal will be maintained and can be linked to other sites. NCAR will continue toingest and archive CXML data after 2014. CMA is assessing the situation andcarrying out internal studies to inform a decision.
There is perhaps the possibility to have complementary centres, not duplicating one
another e.g. for the main global TIGGE data, CXML, observations data, reforecast
datasets, regional EPSs for different regions etc., But there is then the issue of aback-up capability. It would be preferable to see two data centres in the future rather
than just ECMWF.
Regarding NCEP data there will need to be some software changes to transfer
direct data from NCEP and NCDC to ECMWF rather than through NCAR. It will also
be necessary that NCDC has some official status as a TIGGE partner.
Action 11.3.5: WMO secretariat to send a formal letter to NCDC by end of July
2013, to convey appreciation of their work and to request continuation of theprovision of NCEP data to the TIGGE archive after the end of THORPEX.

3.4 Possible changes to TIGGE fields, resolution, additional parameters.
Following THORPEX there are expected to be 3 datasets available i.e. TIGGE,
TIGGE-LAM and the S2S. These are expected to be used by the WWRP projects i.e.
PPP, S2S, HIW, RDPs and FDPs. There is a need to clarify future archiving
requirements e.g. parameters, resolution, time delay, etc., There will also be a needto archive some RDP and FDP datasets. Some examples of new requirements
coming from PPP include sea ice fields, snow cover, ocean wave data,
observational data, reforecast data, short range forecast data etc.,
JMA again stressed the need for some common TIGGE resolution for the middle
and upper atmosphere to limit future data volumes. However, full resolution isdesirable for other fields (e.g. surface data and PV); it is not clear whether mixing
resolutions for different parameters would lead to any technical problems.
It is possible that new TIGGE data providers may be found – one possibility is The
Fleet Numerical Meteorology and Oceanography Center (FNMOC) of the US Navy.
Action 11.3.6: WMO secretariat, in consultation with the co-chairs, to prepare
letter(s) to archive centres by October 2013, with the aim of confirming their plansregarding the future of TIGGE in the post-THORPEX era.

CAS/THORPEX ICSC GIFS-TIGGE-11/Report p. 7

Action 11.3.7: WMO secretariat, in consultation with co-chairs, to prepare a letterto current data providers by October 2013 enquiring about their willingness tocontinue to provide data to the TIGGE archive in the post-THORPEX era.
Action 11.3.8: Craig Bishop to approach FNMOC to sound out their willingness toprovide data to the TIGGE archive in the future. [post-meeting note – FNMOC has
informally indicated a willingness to provide the data but is still assessing theinternal costs of doing so].

3.5 TIGGE-LAM progress and plans (T. Paccagnella)
LAM EPSs are contributing to many projects e.g. HyMeX, FROST etc., The EPS
systems involved in FROST were outlined e.g. COSMO-LEPS, GLAMEPS,ALADIN-LAEF, and NMMB EPS. These are convective parameterised systems.
Some convective permitting systems are also in use e.g. COSMO –RU-EPS,
Harmon EPS (HIRLAM).
An example of a heavy precipitation event in Soichi was shown and the difficulty but
importance of distinguishing rain from snow emphasised. Also local foehn wind
events were important.
The EPS systems contributing to HyMeX were discussed. Several systems are
running. HyMeX has a ten year timescale and wider participation is welcome.
The Typhoon landfall project was outlined and the added value form LAM EPSs
concerning intensification, max. wind, central pressure etc., was noted.
The SRNWP-EPS project is an activity on convective permitting EPSs leading
hopefully to a 3 year EUMETNET proposal for further work.
Regarding archiving CMA continues to archive their own data whilst at ECMWF the
GEOWOW project has funded commencement of archiving data from some LAM
EPSs in Europe. This is expected to expand in the coming year.
It is also recognised that there is a need to consider the future of the TIGGE LAM
panel after the end of THORPEX.
Due to the poor overlapping of integration domains in the Convection Permitting
LAM EPS systems, a valuable contribution to the TIGGE LAM archive would be
represented by datasets collected during RDPs, FDPs and other projects. During
these projects several systems are implemented ad hoc and run on the same region.
This would also allow a wider scientific community to use these projects datasets.
Action 11.3.9: WG members to consider & clarify the future of the TIGGE-LAM
panel after THORPEX and make recommendations to ICSC before EC-66.

4 Links with other THORPEX and WWRP groups
4.1 Links with PDP and proposed Predictability and Ensemble Expert team (C.
Bishop, R.Swinbank)
There is a desire to carry on some of the best aspects of the THORPEX programme
into the future. The TIGGE WG focus has changed from technicalities of thearchives to calibration of ensembles, research on EPS products etc., The group isalso now addressing more basic research issues such evaluation and diagnosis of

CAS/THORPEX ICSC GIFS-TIGGE-11/Report p. 8
EPSs leading to overall improvements. Looking to post-THORPEX arrangements
there is a firm proposal to create a Predictability, Dynamics and Ensemble
Forecasting group which would bridge the operational and academic communities,
promote archiving, focus on scientific issues such as growth of errors, consider
stochastic representation of unresolved processes etc., The group would need good
links to WGNE and other WWRP expert teams. It would be able to provide expert
support to projects such as HIW, PPP and S2S. However, development of severe
weather products could perhaps be transferred to HIW and archive management to
a new liaison group.
Some transition arrangement will be needed and it would make sense to work
towards a merger during 2014. It is important that the new group also helps toaccelerate the take up of TIGGE research in operational centres.
The GIFS-TIGGE WG strongly supported the proposed merger with the PDP WG.
Decision: Members of the GIFS-TIGGE working group agreed in principle to the
proposed merger of the current GIFS-TIGGE WG with PDP WG as outlined in thepaper by the co-chairs of the two working groups.
Action 11.4.1: Co-chairs of both GIFS-TIGGE and PDP working groups to amend
the paper on the proposed merger of GIFS-TIGGE and PDP groups and then submit
it to the two working groups and table it for discussion at ICSC-11, in preparation for
discussion by CAS.
Action 11.4.2: Co-chairs of both GIFS-TIGGE and PDP working groups to consider
the advantages of convening a joint working group meeting early in 2014 to consider
scientific priorities of the proposed merged group.

4.2 Update on the HIW project (J.Keller)
The background to the proposed project was outlined. With PPP and S2S there is
still believed to a “gap” – global high impact weather on timescales from minutes to
2 weeks. The new project is designed to improve predictive skill on thesetimescales in the context of a changing climate. A Workshop was held in Karlsruhe
leading to a draft project plan. This will be submitted to the ICSC and WWRP JSC in
July 2013. A revised proposal will be tabled at CAS in November 2013 and finally
the WMO EC asked to approve the project in June 2014.
The project is aimed at making a step change in the ability of individuals, businesses
and communities to reduce the impacts of adverse weather. Some key project goals
have been defined including improving understanding of the factors determining thepredictability of HIW, enhancing capability to forecast impacts, producing more
relevant forecasts and warnings, growing trust in forecasts and enabling more
effective responses from users.
Some cross cutting activities will include the design of observational systems, field
campaigns, knowledge transfer etc., The research focus will be on convection, TCs,
storm surges, river floods, windstorms etc., Other research goals will addressmodel development, observations, DA and EPSs. Evaluation, addressing
uncertainty and communication of the forecast will be important elements.
The strategy to implement the project will involve developing linkages withinternational bodies, increasing national initiatives, strengthening inter-disciplinary

CAS/THORPEX ICSC GIFS-TIGGE-11/Report p. 9
linkages between academia, research institutions and operational centres andengaging scientists with different backgrounds.
There is a strong interest in the potential contributions of TIGGE and TIGGE-LAM tothe project and in other R and D efforts e.g. T-NAWDEX and HyMeX. There is alsoa need to consider which variables are most useful for the study of HIW and to
identify large scale precursors for HIW.
Action 11.4.3: Working group members to consider how TIGGE and TIGGE-LAM
should best support and contribute to the proposed High-Impact Weather project.

4.3 Links with DAOS (R. Saunders)
The role of this WG was outlined and the upcoming 6th WMO Symposium on DA
was noted. Some current issues in observations were described. Metop-B provides
improved coverage of IASI and ATOVS radiances. The Met Office is now
assimilating both. Impact studies have demonstrated the loss of skill when various
satellite data are removed. There is a distinct benefit in adding more polar orbiting
data.
There is a potential gap in US polar data. NPP was launched in 2012 and the first
JPSS is not due for launch until 2017. However, other data from the Chinese FY-3
and the Indian Oceansat-2 are now proving useful. Also, there is the possibility ofcommercial data supply in the future.
GPS-RO is proving to be a fantastic source of data with excellent coverage but
COSMIC satellite failures are weakening the overall system.
The first steps are now being taken to enable exchange of weather radar data. CBS
is exploring the definition of common formats. Regarding ground based GPS thereis good coverage over Europe and the network in the US is now available. Howeverdata from the rest of the world is limited. There is a need to bring other countries on
stream.
DAOS studies using the current ECMWF forecasting system showed virtually no
impact from the US Winter Storm Reconnaissance Program (WSR). Tests
performed about a decade ago using NOAA’s forecasting system showed that, at
this time, the WSR program had a significant positive impact on the forecasts ofsevere weather events. It is possible that improved modelling and improved use ofsatellite data has reduced the marginal gain realizable from the WSR observations
over the past decade. Thus, the latest investigation of the impact of WSR data on
the ECMWF system has encouraged NOAA to revaluate the benefit of the WSR
program to their current forecasting system. .
Other WG activities related to DIAMET (sting jets over Scotland), T-NAWDEX
planning and HyMeX were outlined.
DA terminology has been revised by the group and will be circulated for comment.
Other interests include using the TIGGE data bases to examine forecast
performance and model errors. The link with the HIW project will be important
especially as regards the necessary improvements to the observations system andusing OSSEs to decide future useful observation sites for extreme weather.
It is expected that after THORPEX the DAOS WG will become a WG of the WWRP
funded by the WMO core budget.

4.4 Update on the S2S project and potential of cloud computing (A. Arribas)

CAS/THORPEX ICSC GIFS-TIGGE-11/Report p. 10

The S2S project was outlined. There is a wide range of participants and big
differences in prediction systems with little commonality and so a challenge in using
the data easily and flexibly. The S2S archive will contain a large number of variables
for the atmosphere and ocean, hindcast data and also sea ice data. This will beinterpolated to a common 1.5 degree resolution. Data submission is expected tostart early in 2014. The archive will not include all the TIGGE variables, just themore common ones.
The Met Office is investing heavily in cloud computing and the application of thisfacility to the S2S project was outlined. Although the main S2S archive will be at
ECMWF it is proposed to offer the most commonly used data through the cloud
facility. This will make it much easier for the user and will open more opportunities
for application of the data by other communities. This approach has been welcomedby the WMO and IRI. A trial with the users will start by the end of next year and the
Met Office is presently able to absorb the cost of this work.
Some of the main interests of the S2S project were then described including the
MJO and land surface research.

4.5 Update on PPP (T. Iversen)
The background to this project was outlined. Final versions of the Science and
Implementation Plans are available from the WMO website. The mission statement
is “to improve weather and environmental prediction in polar regions on timescales
from hourly to seasonal”. Some of the research areas include forecasting system
research (observations, modelling, DA and EPSs), underpinning research(predictability and diagnostics), teleconnections, SERA and verification.
Because of the sparse data coverage in polar regions there are serious verification
issues for e.g. TIGGE data. The large central Arctic area has few observations.
However, the impact of satellite data is already large and becoming even moresignificant.
There are plans to do model development to resolve issues of poor predictability e.g.
blocking. It is clear that coupled models are needed for polar NWP.
A Year of Polar Prediction (YOPP) involving intensive observations and modelling isplanned for 2017/8. The preparatory phase has already started. It is hoped to have aconsolidation and analysis phase in 2018/20.
Regarding TIGGE and the relationship with PPP there are number of interestingquestions e.g. the benefits of multi-model versus single model EPSs, EPS
calibration in polar regions, the paucity of LAM EPS data etc., It was hoped that thenext phase of TIGGE would pay increased attention on polar issues such as midlatitude teleconnections, verification using non-conventional data, the role ofcoupling and other polar scientific issues.

5 EPS research and development
5.1 Initial Conditions: 4D-En Var (N. Bowler)

CAS/THORPEX ICSC GIFS-TIGGE-11/Report p. 11
The 4D-En-Var algorithm was outlined and contrasted with 4D-Var; the En-Var method
uses an ensemble to propagate error covariance information, rather than the tangentlinear (and its adjoint) that are used by 4D-Var. The latter has some advantages i.e. ismore parallelisable and so is able to do DA at high resolution and it can make use oflarger ensembles. Since it has no tangent linear model and so there is no concern overneglected physics schemes. The disadvantages are that it requires a large memory
allocation and makes significant input/output demands, and there is no propagation of
static covariance information.
The mathematics of ensembles of DA was reviewed and a comparison given of thedifferent schemes. En-4D-Var is expensive, En-4D-En-Var is much cheaper and EnKF
is quickest to run but has a high maintenance cost and may need a linear operator.
Currently, 4D-En-Var is found to have poorer performance than 4D-Var. This needs
further investigation; there seem to a number of factors at play. Some single observation
tests are being carried out.
For ensembles in the future it will be necessary to look at inflation methods andinvestigate perturbed observations.
5.2 EnKF and ETR (Y. Zhu)
The characteristics of the planned improvements to the NCEP Global Ensemble
Forecast System (GEFS) were outlined. It will include updated global DA and global
deterministic and ensemble models.
The GFS model upgrade (V10), includes a semi-lagrangian approach, more accurate
spectral grid transforms, improvements to physics. High resolution SST analysis andsea ice analyses will be used.
Meanwhile, GEFS initial and stochastic perturbations are being improved. In initial tests
with hurricane Sandy, significant improvements were noted i.e. more ensemble
members moved the hurricane north-west and provided better advice than theoperational model which is 7-day ahead before landing.
5.3 Stochastic physics (W. Tennant)Various apects were outlined including a random parameter scheme, stochastic KE
backscatter (SKEB), stochastic perturbed physics tendencies, vorticity confinement,
stochastic convection parameterisation, and surface perturbations.
The SKEB scheme was considered in some detail. Tracked storms are more intensewith SKEB2 but have slightly better position without the scheme. In the tropics thescheme improves the divergence field and the precipitation rate. It also provides a better
wind field over the Arabian sea and over India. However, the scheme needs to be
retuned to compensate for the more active dynamical core of ENDGame.
5.4 Stochastic convective trigger for HWRF (Y.Zhu)
Storm intensity has been found to be very sensitive to the convective trigger but theintensities do not respond linearly to the trigger function. The latest version of HWRF
ensemble has been tested for past two seasons, the improvements of intensity and trackerrors are encouraged. But, some important questions need to be answered e.g. thereason for large intensity variations. These will form the basis for future work.
5.5 Canadian GEPS (L. Wilson)

CAS/THORPEX ICSC GIFS-TIGGE-11/Report p. 12

Details of some experiments with the old and new systems were outlined. The latest
version of GEPS is V3.0. Improvements in the upper air have been noted as have the
NAEFS forecasts. The ensemble is more stable computationally (by limiting physics
perturbations in high CAPE areas, shorter time steps and filtering). The Canadian centre
is now in the TIGGE data set for 2m temperature.
Big differences in verification scores have been noted, depending on whether own or
ERA interim analysis data are used.
5.6 PDP working group and EPSs (C. Bishop)
The PDP WG topics of interest were outlined including the experimental field campaigns
T-NAWDEX/DOWNSTREAM, DIAMET, HYMeX and T-PARC. Some of the WG
members are active participants in these programs. In the area of EPSs, recent work on
measuring the ability of ensemble variances to track true flow dependent error variance
was described as was a new approach for post-processing multi-model ensembles.
Measures of the ability of ensemble variance to track true flow dependent error variance
may prove useful in the development of stochastic representations of sub-grid scale
processes. Ideally, the inclusion of stochasticity in such schemes should increase theability of the ensemble variance to track true flow dependent error variance. New PDP
work on the “relative error variance of variance prediction” or “effective ensemble size”
measure of ensemble performance described in Bishop et al’s (2013, MWR) papers on
hidden error variance theory provide a promising means of testing whether stochastic
physics schemes are increasing or decreasing the ability of ensemble variance to tracktrue error variance.
The TIGGE ensemble archive is similar to the ensemble archives associated with those
constructed as part of the Coupled (climate) Model Inter-comparison Project (CMIP) inthat it is constructed from ensemble forecasts contributed from a variety of agencies.
Undoubtedly, some models are more skilful than others and some of the ensembles
have been more accurately constructed than others. How then should the informationfrom all of these sub-ensembles be optimally combined? Other recently published PDP
work shows that one way of dealing with this problem is to mathematically transform themulti-model ensemble of ensembles so that it is similar to ensemble of perfect models inthat (i) the transformed ensemble mean is the linear combination of transformed
ensemble members that minimizes the distance from observations in both in-sample andout-of-sample tests, and (ii) the mean square distance of the transformed ensemble fromobservations is equal to the variance of the transformed ensemble. In tests, this new
approach outperformed existing approaches. It is hoped that funding will be obtained toapply this new approach to the TIGGE ensemble in addition to the CMIP ensembles.

6 Applications of TIGGE data
6.1 Status and plans of the SWFDP (K.Mylne)
An update was provided of the SWFDPs. The main objective is to improve warning
services of severe weather in developing countries. A cascade process is operated
from the global centres to a regional centre and then down to the individual NMHSCAS/THORPEX ICSC GIFS-TIGGE-11/Report p. 13
which retain their national responsibilities for issuing advice. All information is sent ascharts. New satellite and imaging tools are being brought in to aid nowcasting.
There are a number of SWFDP regional projects. In East Africa, a regional project has
recently been started, centred around Lake Victoria. A specific focus is on storms on
the lake, considering strong winds, heavy precipitation and hazardous waves. Morethan 3000 people die each year in boating accidents. However, verification is difficult
due to lack of observations.
The Southern Africa SWFDP is progressing well and good progress is being made withthe other initiatives in the South Pacific Islands, Eastern Africa, Southeast Asia and the
Bay of Bengal. Whilst the SWFDPs are keen to engage and support new prototype
products they do not wish to make big demands locally or form a distraction from themain work.
There is a real need to improve forecasts of tropical convection and localised eventsand to improve forecasting tools for the very short range i.e. less than 12h ahead. On
the TIGGE side moving the multi-model tropical precipitation forecasts to near real time
will be very important. Developments to visualise hazards are also desirable e.g. theMet office global hazards map and overlays showing roads, population density etc.
The SWFDP program is run based on voluntary contributions. Further funding isneeded so an approach to the World Bank is being made.

6.2 Progress in SWFDP/GIFS-TIGGE collaboration (R.Swinbank, M. Matsueda)
The “TIGGE Museum” web pages were outlined. These relate to probabilistic extreme
weather. Maps covering the polar regions have now been added for the PPP project.
Summaries of extreme weather over the whole globe are also now presented. People
in developing countries are able to access the website. Some examples were showne.g. of the 2010 Russian heatwave (all the models showed good performance), thePakistan Floods (NCEP was much better), Hurricane Irene (JMA was better) and
Hurricane Sandy (ECMWF had much better performance). Thus it is clear that the best
performance varies from centre to centre in different forecast cases.
Objective verification of the severe weather products demonstrated that the grandensemble forecasts are better than those from ECMWF or any other single-model
ensemble.
The GEOWOW project will allow these probabilistic products to be generated in realtime and supplied to SWFDP forecasters for evaluation.

6.3 GEOWOW project and hydrological applications (F. Pappenberger)
The TIGGE hydrological EPS, TIGGE-HEPS was described. The activehydrometeorological community is mainly in HEPEX. This project is very end-user
focused. A new science plan is currently being written. The European Flood Awareness
System (EFAS) was outlined. The major floods in central Europe in June 2013 were
well forecast with a lead time of 4-5 days.
At least 12 publications using TIGGE data in hydrology have appeared in the literature.
Flooding is expected to be a good application area in the HIW project.
Some aspects of the GEOWOW project were described especially the work related to
global river run off and comparison with observations.

CAS/THORPEX ICSC GIFS-TIGGE-11/Report p. 14
6.4 NW Pacific TC Intercomparison (M. Yamaguchi)
Studies of TC forecasting using TIGGE data were outlined. There are 14 papers in theliterature, 2 were application orientated, 6 looked at benefits of the grand ensemble
approach and 6 considered dynamics and predictability.
Some inter-comparison verification results were shown for TC track predictions in thewestern North Pacific. The ensemble mean was shown to perform better than thecontrol. Combining 3 ensemble centres improves the Brier skill score of TC strike
probability forecasts with respect to the best single model ensemble.
Verification of TC genesis in the North Indian Ocean and the western North Pacific wasdescribed. Probabilistic forecasts of TC activity are skilful compared to climatologicalforecasts in week 1. For the ECMWF one month EPS, in the western North Pacific, it
was shown that the hit rate was high, miss rate small but the false alarm rate was alsohigh.
The status of the CXML data exchange was reviewed. Nine centres providing data arelisted. However, China and JMA only provide data for the western North Pacific.
Extension of the CXML messages may be beneficial to advance studies and improve
TC genesis and intensity forecasts.

6.5 Progress with the TIGGE review paper (R. Swinbank)
Limited progress had been made on this topic. A proposal for the content of the paper
was reviewed and further contributors indentified.
Action 11.6.1: Co-chairs & other co-authors to prepare a draft TIGGE review paper
within the next 6 months with intention of publishing it in BAMS.

7 Membership
Anticipated changes were reviewed. It is expected that a replacement for Laurie Wilson
will be announced in a few weeks time. The co-chairs thanked Laurie for his excellent
contributions to the WG over a number of years.

8 Any other business
There was no additional business.

9 Review of meeting outcomes, decisions and actions, next meeting
9.1 Discuss ICSC report
It was agreed that the paper to ICSC would include an update of the status of TIGGE,
recent scientific papers, a section on the future of the archive, a note the CXML
requests and also discussion of the future arrangements for the working group.

CAS/THORPEX ICSC GIFS-TIGGE-11/Report p. 15
9.2 Review of decisions and actions
The actions and decisions were reviewed and agreed

9.3 Next meeting
The next meeting is likely to be held in conjunction with the PDP WG in early 2014 andwill discuss a road map to merger of the two groups.

CAS/THORPEX ICSC GIFS-TIGGE-11/Report p. 16
PARTICIPANTS
1)

GIFS-TIGGE WORKING GROUP
Richard Swinbank (Co-chair)
Masayuki Kyouda (Co-chair)David Richardson
Gong Jiandong
Mike Naughton
Seung-Woo Lee
Christopher Cunningham (for Osvaldo Moraes)
Laurie Wilson
Doug Schuster
Yuejian Zhu
Tiziana Paccagnella

3)

WWRP / THORPEX WG REPRESENTATIVES
Allberto Arribas (Met Office) – S2S project
Craig Bishop (NRL) – PDP
Roger Saunders (Met Office) – DAOS
Trond Iversen (NMI) – PPP
Julia Keller (KIT) – HIW project4)

INVITED EXPERTS
Munehiko Yamaguchi (JMA/MRI, visiting ECMWF) – TC forecast inter-comparsion
Florian Pappenberger (ECMWF) – hydrological apps: GEOWOW
Warren Tennant (Met Office) – Stochastic physics
Neill Bowler (Met Office) - 4D-Ensemble-Var
Mio Matsueda (Oxford) – severe weather products
Ken Mylne (Met Office) – SWFDP

5)

WMO SECRETARIATJim Caughey
Tetsuo Nakazawa

CAS/THORPEX ICSC GIFS-TIGGE-11/Report p. 17
Actions and Decisions GIFS-TIGGE WG 11
Permanent Actions
Action P.1: All archive centres to update statistics on TIGGE data users on an annual basis(end of each year), using similar statistics for users, actives users, etc. Doug Schuster tocoordinate.
Action P.2: Yuejian Zhu to carry out literature search for papers based on TIGGE data on anannual basis (end of each year), and summarise results. Archive centres to ask users to informthem when TIGGE papers are written, to enable the list of TIGGE publications to be kept up to
date.
Action P.3: All data providers to provide model descriptions in agreed Excel format and to
update the files after significant changes and send to ECMWF.
Action P.4: Co-chairs to request reports before each WG meeting on all actions, plus relevant
progress reports.
Action P.5: WG members to consider adding to training material on the TIGGE data portals,
including data access and manipulation examples, to help potential users of the TIGGE archive.

Actions & Decisions
Action 10.6.3 The WG encourages providing centres to include information on forming
tropical storms in CXML messages (initially using location / time as identification andsubsequently discuss a naming convention).
Action 10.7.1 Christopher Cunningham to consult with Tiziana Paccagnella to ensuretransfer of benefits from the TIGGE-LAM work to the La Plata Basin Project
Action 11.3.1: Yuejian Zhu to inform ECMWF of the name of technical contacts at NCEP and
NCDC to liaise over the practicalities of providing the NCEP data to the ECMWF archive centre,
by end of July 2013.
Actions 11.3.2: The working group requests Christopher Cunningham and Yuejian Zhu toensure that missing data from CPTEC and NCEP is minimised by liaising with contact points to
respond to requests from archive centres to fill any gaps.
Action 11.3.3: Archive centres are requested to investigate which types of TIGGE data aremost widely used.
Action 11.3.4: JMA and CMA are requested to consider extending CXML tropical cyclone
forecast data to all ocean basins.
Action 11.3.5: WMO secretariat to send a formal letter to NCDC by end of July 2013, toconvey appreciation of their work and to request continuation of the provision of NCEP data to
the TIGGE archive after the end of THORPEX.

CAS/THORPEX ICSC GIFS-TIGGE-11/Report p. 18
Action 11.3.6: WMO secretariat, in consultation with the co-chairs, to prepare letter(s) toarchive centres by October 2013, with the aim of confirming their plans regarding the future of
TIGGE in the post-THORPEX era.
Action 11.3.7: WMO secretariat, in consultation with co-chairs, to prepare a letter to current
data providers by October 2013 enquiring about their willingness to continue to provide data to
the TIGGE archive in the post-THORPEX era.
Action 11.3.8: Craig Bishop to approach FNMOC to sound out their willingness to provide data
to the TIGGE archive in the future.
Action 11.3.9: WG members to consider & clarify the future of the TIGGE-LAM panel after
THORPEX and make recommendations to ICSC before EC-66.
Decision: Members of the GIFS-TIGGE working group agreed in principle to the proposed
merger of the current GIFS-TIGGE WG with PDP WG as outlined in the paper by the co-chairsof the two working groups.
Action 11.4.1: Co-chairs of both GIFS-TIGGE and PDP working groups to amend the paper on
the proposed merger of GIFS-TIGGE and PDP groups and then submit it to the two working
groups and table it for discussion at ICSC-11, in preparation for discussion by CAS.
Action 11.4.2: Co-chairs of both GIFS-TIGGE and PDP working groups to consider theadvantages of convening a joint working group meeting early in 2014 to consider scientificpriorities of the proposed merged group.
Action 11.4.3: Working group members to consider how TIGGE and TIGGE-LAM should best
support and contribute to the proposed High-Impact Weather project.
Action 11.6.1: Co-chairs & other co-authors to prepare a draft TIGGE review paper within thenext 6 months with intention of publishing it in BAMS.

CAS/THORPEX ICSC GIFS-TIGGE-11/Report p. 19
Abbreviations and acronyms
Acronyms
Full spelling
BOM
Bureau of Meteorology (Australia)
CXML
Cyclone XML
CAS
Commission for Atmospheric Sciences
CMA
China Meteorological Administration
CMIP
Coupled (climate) Model Inter-comparison Project
COSMO
COnsortium for Small-scale MOdelling
CPTEC
Centro de Previsao de Tempo e Estudos Climaticos (in Portuguese)DA
Data Assimilation
DACA 13
Davos Atmosphere and Cryosphere Assembly 2013
DAOS WG(THORPEX) Data Assimilation and Observing Systems Working Group
DIAMET
DIAbatic influences on Mesoscale structures in Extratropical sTorms
EC(WMO) Executive Council
ECMWF
European Centre for Medium-Range Weather Forecasts
ENDGameEven Newer Dynamics for General atmospheric modelling of theenvironment
EFAS
European Flood Awareness System
EPS
Ensemble Prediction System
ERA
ECMWF Re-Analysis
FDP
Forecast Demonstration Project
FNMOC
Fleet Numerical Meteorology and Oceanography Center
FROST
Forecasting and Research: the Olympic Sochi Testbed
GDPFS
Global Data-processing and Forecasting System
GEFS
Global Ensemble Forecast System
GEOSS
Global Earth Observation System of Systems
GEOWOWGEOSS Interoperability for Weather, Ocean and Water
GIFS
Global Interactive Forecasting System
GIFS-TIGGE(THORPEX) GIFS-TIGGE Working GroupWG
GLAEPS
Grand Limited Area EPS
GSI
Gridpoint Statistical Interpolation
HEPEX
Hydrologic Ensemble Prediction EXperiment
HIW
High-Impact Weather
HyMeX
Hydrological Cycle in Mediterranean Experiment
ICO
International Coordination Office (of WMO project)
ICSC(THORPEX) International Core Steering Committee
IPO(THORPEX) International Program Office
JSC
Joint Scientific Committee
JMA
Japan Meteorological Agency
KMA
Korea Meteorological Administration
MJO
Madden Julian Oscillation

CAS/THORPEX ICSC GIFS-TIGGE-11/Report p. 20

MOGREPS
NAEFS
NCAR
NCDC
NCEP
NMHS
NRL
NWP-TCEFPOSCPDP WG
PPP
RDP
S2S
SERA
SKEB
SRNWP-EPS
SWFDP
T-PARC
T-NAWDEX
TC
THORPEXTIGGE
TIGGE-LAM
Var or VAR
WSR program
WMO
WWRP
YOPP

Met Office Global and Regional Ensemble Prediction System
North American Ensemble Forecast System
National Center for Atmospheric Research
National Climatic Data Center
National Centers for Environmental Prediction
National Meteorological and Hydrological Service
U.S. Naval Research Laboratory
North Western Pacific Tropical Cyclone Ensemble Forecast ProjectOpen Science Conference(THORPEX) Predictability and Dynamical Processes Working Group
Polar Prediction Project
Research and Development ProjectSub-seasonal to Seasonal Prediction Project
Societal and Economic Research Applications
Stochastic Kinetic Energy Backscatter
Short Range Numerical Weather Prediction EPS
Severe Weather Forecasting Demonstration Project
THORPEX Pacific Asian Regional Campaign
THORPEX - North Atlantic Waveguide and Downstream Impact Experiment
Tropical Cyclone
THe Observing system Research and Predictability EXperiment
THORPEX Interactive Grand Global Ensemble
Limited Area Model component of TIGGE
VARiational (assimilation)
US Winter Storm Reconnaissance Program
World Meteorological Organization
World Weather Research ProgrammeYear of Polar Prediction