A holistic review informing the Thorpex legacy Gilbert Brunet WWRP/JSC Chair

1. A holistic review informing the Thorpex legacyGilbert BrunetWWRP/JSC Chair CAS MG meeting, 23-25 May 2013 Geneva

2. Rationale

3. The Strategic Plan for the Implementation of WMO’s World Weather Research Programme (WWRP): 2009 – 2017 (WMO/TD-No. 1505). The WWRP strategic plan integrates WMO Member activities in THORPEX, tropical meteorology, mesoscale weather forecasting, nowcasting, verification and societal and economic applications with those of partners in global and regional forecast research and Earth observation. The plan maintains and reinforces the traditional strong links with GAW, the World Climate Research Programme (WCRP) and other WMO activities. Implementation activities outlined in the first Strategic Plan will address cross cutting activities at the interface of nowcating-mesoscale, mesoscale-global and weather-climate prediction research, research-operations that are related to the delivery of a weather and climate services; in particular, ensemble weather prediction systems, tropical convection, polar prediction; and sub-seasonal to seasonal prediction. WWRP - General

4. 2011 WMO Congress: Future of WWRP 3.3.40 Legacy of THORPEX “mid-term review of the THORPEX Programme.” “THORPEX had become an integral component of the WWRP focusing on global scales and that the WWRP should fulfill the THORPEX high priority research activities for the next biennium if and when contributions to the THORPEX trust fund begin to “tail off” towards the end of the ten-year period of the programme.” 3.3.41 An Earth-system Prediction Initiative “ WWRP community needs to participate in the establishment of the international Earth-system Prediction Research Initiative in order to accelerate advances in weather, climate and Earth-system prediction.” “ Elements of the Initiative are introduced in a compendium of papers that appeared in the October 2010 issue of the Bulletin of the American Meteorological Society (BAMS)”

5. 2011 WMO Congress: Future of WWRP 3.3.43 An Earth-system Prediction Initiative Congress recognized that the proposed initiative needs to be aligned and built on the projects already initiated by WWRP and THORPEX on sub-seasonal and seasonal forecasts and polar research or endorsed like HYMEX. Two important components of this initiative have been discussed: (i) Earth-system Interdisciplinary Summer School Program: a first step toward informing the next generation of the excitement and opportunities of the research and multifaceted deliverables at the forefront of society; and (ii) the first WWRP Earth-system Open Science Conference.

6. 2005 2014 Accelerating improvements in the accuracy of one-day to two weeks high-impact weather forecasts for the benefit of society, economy and environment A photographic collage depicting the societal, economic and ecological impacts of severe weather associated with four Rossby wave-trains that encircled the globe during November 2002.

7. What is THORPEX? • THORPEX was established in May 2003 by the Fourteenth World Meteorological Congress as a ten-year international global atmospheric research and development programme under the auspices of the WMO Commission for Atmospheric Sciences (CAS). • Organization structure: ICSC/EC Regional committees DAOS WG Data Assimilation and Observing Systems PDP WG Predictability and Dynamical Processes GIFS-TIGGE WG Global Interactive Forecasting System – THORPEX Interactive Grand Global Ensemble

8. 8

9. 9 A. Doerenbecher

10. T-PARC Summer Phase (2008): Overall impact of dropwindsondes on TC track 10 Weissmann et al. (2011)

11. Typhoon Sinlaku (2008): Satellite AMVs HOURLY AMVS INCLUDED ALL AMVS REMOVED RAPID-SCAN ADDED 11 Adapted by Rolf Langland from Berger et al. (2011)

12. 2011 Winter Storm Reconnaissance: ECMWF data denial 22 high, 62 medium, 14 low-priority cases, and 776 dropwindsondes deployed. Target verification times from +12 to +120 h. 12 Hamill et al. (MWR 2013)

13. Scatterplot of impacts For each case where dropsondes were launched, a downstream target location and verification time are identified. Data are plotted here only for these times/target locations. Verification area here is a +/- 10 degree box centered on target. Verification norm is an approximation to the total-energy norm. Cases above line indicate benefit from targeted data. No obvious beneficial impact.

14. Observation targeting - Conclusions • Observations primarily targeted to attempt to improve short-range (1-3 day) forecasts. • Tropical cyclones: track forecasts mostly beneficial statistically, recent systematic evaluations lacking. • Extratropics: value of targeted data small but positive on average, needs further evaluation. • Recognize that forecast skill is improving due to improved resolution, observations, DA, physics. Hence, the average marginal impact of an individual observing system is decreasing. • Open question: what is the overall cost-effectiveness of targeted observations? 14

15. TIGGETHORPEX Interactive Grand Global Ensemble A major component of THORPEX: a WMO World Weather Research Programme to accelerate the improvements in the accuracy of 1-day to 2-week high-impact weather forecasts GEO task WE-01-C1 – “Global Multi-Model Prediction System for High-Impact Weather” Objectives: Enhance collaboration on ensemble prediction, both internationally and between operational centres & universities. Facilitate research on ensemble prediction methods, especially methods to combine ensembles and to correct systematic errors Enable evolution towards a prototype operational system, the “Global Interactive Forecast System” Website: http://tigge.ecmwf.int

16. TIGGE data Ten of the leading global forecast centres are providing regular ensemble predictions to support research on predictability, dynamical processes and the development of probabilistic forecasting methods. TIGGE data is made available for research after a 48-hour delay. NB. Not designed for operational use. TIGGE data flows

17. TIGGE Research Following the successful establishment of the TIGGE dataset, the main focus of the GIFS-TIGGE working group has shifted towards research on ensemble forecasting. Particular topics of interest include: a posteriori calibration of ensemble forecasts; combination of ensembles produced by multiple models; research on and development of probabilistic forecast products. We now also cover improvement of ensemble prediction systems, including: representing uncertainties in initial conditions stochastic physics & other techniques to account for model error TIGGE data is also invaluable as a resource for a wide range of research projects. Over 70 articles related to TIGGE have been published in the scientific literature

18. Example Tropical Cyclone ProductsMOGREPS-15: Ma-On, 12Z Fri 14th July 2011 Left hand plot: 24 ensemble tracks Middle plot: strike probability – i.e., probability that the storm will be within 75 miles within the next 15 days. Right hand plot: MOGREPS ensemble mean (blue), control (cyan), previous observations (red) and deterministic track (green) Met Office TC products courtesy Piers Buchanan, Helen Titley and Julian Heming

19. Warnings of other severe weather events • More recently, prototype products have been developed based on gridded forecast data, such as this product which highlights the risk of heavy rainfall. • Similar products also available for • hot & cold temperatures, • strong winds Prototype product courtesy Mio Matsueda JMA/MRI, now Oxford University

20. WMO Severe Weather Forecasting Development Project (SWFDP) WMO Vision for improving severe weather forecasting and warning services in developing countries “NMHSs in developing countries are able to implement and maintain reliable and effective routine forecasting and severe weather warning programmes through enhanced use of NWP products and delivery of timely and authoritative forecasts and early warnings, thereby contributing to reducing the risk of disasters from natural hazards.” (World Meteorological Congress, 2007 and 2011) WMO Strategic Priorities • Disaster Risk Reduction • Capacity Development • Climate change adaptation SWFDP Main Goals • Improve Severe Weather Forecasting • Improve lead-time of Warnings • Improve interaction of NMHSs with users: media, disaster management, civil protection authorities

21. SWFDP Cascading Forecasting Process User communities, including Disaster Management authorities Global Centres RSMC Pretoria NMCs Global NWPcentres to provide available NWP/EPS and sat-based products, including in the form of probabilities, cut to the project window frame; Regional centres to interpret information received from global centres, prepare daily guidance products (out to day-5) for NMCs, run limited-area model to refine products, maintain RSMC Web site, liaise with the participating NMCs; NMCs to issue alerts, advisories, severe weather warnings; to liaise with user communities, and to contribute feedback and evaluation of the project; NMCs have access to all products, and maintained responsibility and authority over national warnings and services. 26

22. Current coverage and future of the SWFDP Current SWFDP regional projects • Southern Africa (ongoing; 16 countries; RSMC Pretoria, RSMC-TC La Réunion) • Southwest Pacific Islands (ongoing; 9 Island States; RSMC Wellington, RSMC-TC Fiji) • Eastern Africa (ongoing, 6 countries; RSMC Nairobi, RFSC Dar) • Southeast Asia (in development, 5 countries; RFSC Hanoi) • Bay of Bengal (in development, 6 countries; RSMC-TC New Delhi) Future plans • More countries, new regions (over 100 countries: developing and least developed countries) • Wider range of hazards • Beyond day-5 (short-, medium-, monthly, and seasonal time-scales) • Collect evolving requirements for the Basic Systems, including to WIGOS and WIS. • Vehicle for introducing promising R&D • Project Office • Regular budget and extrabudgetary resources

23. TIGGE links with SWFDP The TIGGE partners are collaborating with WMO Severe Weather Forecast Demonstration Project (SWFDP) and other FDPs and RDPs, to contribute to development of a future Global Interactive Forecast System. Products developed using TIGGE data will be delivered to and evaluated by SWFDP forecasters to ensure that products address needs of operational forecasters and end users; to provide an environment for the evaluation of prototype products. GIFS-TIGGE will use the global-regional-national cascade pioneered by the SWFDP.

24. Post-THORPEX: WWRP structure and links to WCRP 29 29

25. THORPEX Legacy PCPI MJO TF WGSIP WGDAOS WGPDP Subseasonal to Seasonal Prediction Project JWGFVR WGNR /MFR High Impact Weather Project Polar Prediction Project WGNE SWFDP WGSERA WGTMR 30

26. Proposed High-impact Weather Project • THORPEX has been a major contributor to the advancement of weather forecasting capability. • However, some important areas were omitted from THORPEX, and other areas have gained in importance as a result of external change. • It was agreed by the THORPEX ICSC that there was a need for a new project, focussing particularly on small time and space scales, on the environmental, human & economic impacts of weather, and on the need to communicate weather forecasts in ways that ensure that produce beneficial responses. • A meeting was held in Karlsruhe in March to discuss a possible third “THORPEX legacy” project.

27. MOGREPS-UK example – yellow warning for gales in Orkneys & Shetlands 14-15 Dec 2012 36hr forecast 30hr forecast

28. Outcome of HIW workshop • Agreed to develop HIW project proposal • Strategy: Science, driven by the aim of achieving a step change in global resilience to weather impact, for example on • Environment (flooding); • Transport (aviation); • Economics (energy), • Other areas, e.g., including agriculture, health. • Scope: Understanding & multi-scale modelling of hazards & impacts, communication, evaluation • Links with other initiatives, including SWFDP, and field campaigns (e.g. T-NAWDEX) • Next steps: task team to develop project proposal for future discussion by THORPEX ICSC & WWRP JSC.

29. Ensemble data to support future research • Since TIGGE has proved an invaluable resource for research during THORPEX, it is planned to continue TIGGE and build on its success. • A trio of complementary datasets: • TIGGE project (global medium-range EPS), since October 2006. • TIGGE-LAM project, limited area counterpart to TIGGE, will be an additional resource for HIW project – European LAM-EPS data now starting to be archived at ECMWF. • Sub-seasonal to Seasonal archive to support S2S project – coming soon. • All planned to use similar GRIB2 format and conventions. • Technical liaison group (representatives from data providers & archive centres) to manage. • Proposed new Predictability & Ensembles expert term to provide scientific expertise.

30. Conclusions • THORPEX has been a major contributor to the advancement of weather forecasting capability, especially global NWP. • Its structures (e.g., TIGGE) are increasingly used in wider research. It is important for these elements continue & achieve further advances in the post-THORPEX era. • However, some important areas were omitted from THORPEX, and other areas have gained in importance as a result of external change, motivating the establishment of new projects on: • Polar Prediction • Sub-seasonal to Seasonal Prediction • High-impact weather

31. Thank you! Merci!