1. WWRP Sub-seasonal to Seasonal Prediction (1-90 days) - A Seamless Approach WWRP/THORPEX, WCRP Kick off meeting on Sub- seasonal to Seasonal Prediction (Geneva, 2-3 December 2011) Gilbert Brunet WWRP/JSC Chair Environment Canada

2. WWRP An Earth-System Prediction Initiative  An Earth-System Prediction Initiative for the Twenty-First Century (Shapiro et al.)  Addressing the Complexity of the Earth System (Nobre et al.)  Toward a New Generation of World Climate Research and Computing Facilities (Shukla et al.)  Collaboration of the Weather and Climate Communities to Advance Subseasonal-to-Seasonal Prediction (G. Brunet, M. Shapiro, B. Hoskins, Mitch Moncrieff, Randal Dole, G. Kiladis, B. Kirtman, A. Lorenc, R. Morss, S. Polavarapu, D. Rogers, J. Schaake and J. Shukla

3. WWRP Centres participating in the WMO Long Range Forecast Verification System http://www.bom.gov.au/wmo/lrfvs/index.html  WMO Commission for Basic System prediction time range definitions  MEDIUM-RANGE WEATHER FORECASTING:  BEYOND 72 HOURS AND UP TO 240 HOURS DESCRIPTION OF WEATHER PARAMETERS  EXTENDED-RANGE WEATHER FORECASTING:  BEYOND 10 DAYS AND UP TO 30 DAYS DESCRIPTION OF WEATHER PARAMETERS, USUALLY AVERAGED AND EXPRESSED AS A DEPARTURE FROM CLIMATE VALUES FOR THAT PERIOD.  LONG-RANGE FORECASTING:  FROM 30 DAYS UP TO TWO YEARS  CLIMATE FORECASTING :  BEYOND TWO YEARS

4. WWRP Predicting the Low Frequency Variability Extended-range forecasting of the NAO with the Canadian GEM Monthly ensemble prediction System Medium-range forecasting the 500hPa height with the ECMWF deterministic prediction system The low frequency variability (AO, PNA, Atlantic blockings, …) controls significantly the distribution of high-impact weather (like the Atlantic storm track and equatorial westerly duct) Baroclinic variability (80%) Low frequency variability (dim. ~ 12, 20%)

5. WWRP Collaboration of the Weather and Climate Communities to Advance Subseasonal-to-Seasonal Prediction: Research Issues  The multi-scale organisation of tropical convection and its two-way interaction with the global circulation;  Data assimilation for coupled models as a prediction and validation tool for weather and climate research;  Seamless weather/climate prediction with Multi-model Ensemble Prediction Systems (MEPSs);  Utilization of sub-seasonal predictions for social and economic benefits.

6. WWRP Forecasting-system improvement at ECMWF % % Historical trend Updated from Simmons & Hollingsworth (2002) Acknowledgements to A. Simmons Historical re-forecast project trend using re-analyses

7. WWRP North America Z500 RMSE for the control experiments and latest upgrades of the MSC global analysis-forecast system (January and February 2007) Acknowledgements to S. Laroche

8. WWRP Data assimilation for coupled models as a prediction and validation tool for weather and climate research  Promote research towards the development of a composite data assimilation system, applying different assimilation steps to different scales (weather to climate time-scales) and components (atmosphere, land, ocean, atmospheric composition) of the total Earth system model;  Promote the need to test climate models in a deterministic prediction mode, as started within Transpose-AMIP. The seasonal prediction time frame provides a valuable opportunity to do this;  Promote the use of advanced data assimilation methodologies for parameter estimation, both in weather and climate models, through close collaboration with model developers to interpret assimilation results;  Promote interdisciplinary research on data assimilation methods appropriate for the next generation of re-analysis projects aimed at developing historical records for climate studies.

9. WWRP Seamless weather/climate prediction with Ensemble Prediction Systems(EPSs)  Terms of reference for collaboration between WCRP CLIVAR Climate-system Historical Forecast Project (CHFP) and the THORPEX Interactive Grand Global Ensemble (TIGGE) must be establish for experimentation and data sharing for sub-seasonal to seasonal historical forecasts ( weeks to season) including the required infrastructure.  The requirements for both ensemble prediction methods and greatly increased spatial resolution imply substantial future requirements for computational power and for data storage and delivery capacity.  Development and use of ensemble based modeling methods in order to improve probabilistic estimates of the likelihood of high-impact events.

10. WWRP MJO connection to Canadian surface air temperature: high-impact weather? Lagged winter SAT anomaly in Canada Significant warm anomaly in central and eastern Canada 1-2 pentads after MJO phase 3

11. WWRP Utilization of Sub-Seasonal and Seasonal Predictions for Social and Economic Development  A need for closer ties between weather and climate research:  Understanding how information at the weather/climate interface, including uncertainty, connects with decision-making  There is also a great need for much easier access to forecast data by the user community. These need to be available in special user-oriented products. How to achieve this service?  The post-processing techniques that are needed by many users may require an archive of past forecasts (e.g. for water cycle applications). Some user applications require an archive of re-forecasts from fixed models for periods as long as 20 years or more.

12. WWRP

13. World Meteorological Congress WWRP World Meteorological Organization 2011 Congress Polar Prediction project – “Congress acknowledged the success of the ten projects of the International Polar Year THORPEX cluster, and supported the CAS recommendation that, as a legacy of the IPY, a THORPEX Polar Research project be established to improve the understanding of the impact of high impact weather over Polar Regions. Congress also emphasized the need to have an adequate observational and telecommunication network for the Polar Regions in order to provide the relevant high impact weather services for the region. “ “Congress strongly urged all those concerned to ensure that such a Polar Prediction Research project is established in support of, inter alia, the Global Framework for Climate Services. Furthermore, the EC-PORS, at its Second Session in Hobart in October 2010, agreed to the concept of a major decadal initiative to develop a Polar Prediction System (Global Integrated Polar Prediction System - GIPPS). Congress recognized the importance of effective coordination between these various initiatives, and invited Members to contribute as appropriate. “ Sub-seasonal to Seasonal Prediction – “Congress noted that the JSCs of the WWRP and the JSC for WCRP and WWRP/THORPEX ICSC set up an appropriate collaborative structure to carry out and international research initiative on sub-seasonal to seasonal forecasting. This initiative should be closely coordinated with the CBS infrastructure for long-range forecasting and with the future developments of climate service delivery and the Global Framework for Climate Services. “ “Congress was pleased to note that the WWRP-THORPEX / WCRP workshop on “Sub-seasonal to seasonal prediction” (Exeter, December 2010) had recommended the establishment of a Panel/Project for Sub-seasonal Prediction Research and Applications - Panel members being drawn from WWRP- THORPEX, WCRP, CBS, CCl, JCOMM, CHy, CAS and CAgM and their relevant programme bodies. “

14. WWRP Sub-seasonal to seasonal prediction The Report from the Workshop on “Sub-seasonal to Seasonal Prediction” (Met Office, Exeter 1 to 3 December 2010) has been published to the web (http://www.wmo.int/pages/prog/arep/wwrp/new/documents/reco mmendations_final.pdfhttp://www.wmo.int/pages/prog/arep/wwrp/new/documents/reco mmendations_final.pdf  The major Workshop recommendation was that a Project for sub- seasonal to seasonal prediction research should be established  Planning Group should include representatives from WWRP- THORPEX, WCRP, CBS and CCl and their relevant programme bodies.  The first task for the Planning Group should be the preparation of an Implementation Plan, which is consistent with the contents of the Workshop Report and Recommendations. 99

15. WWRP Sub-seasonal contd. The Implementation Plan should give high priority to:  Sponsorship of a few international research activities  The establishment of collaboration and co-ordination between operational centres undertaking sub-seasonal prediction to:  ensure, where possible, consistency between operational approaches to enable the production of data bases of operational sub-seasonal predictions to support the application of standard verification procedures and a wide-ranging programme of research  Facilitating the wide-spread research use of the data collected for the CHFP - Climate-system Historical Forecast Project (and its associate projects), TIGGE and YOTC for research  The establishment of a series of regular Workshops on sub- seasonal to seasonal prediction  10

16. WWRP Sub-seasonal to Seasonal Prediction Initiative Planning Group  Planning Group Co-Chair 1 Frédéric Vitart ECMWF (WWRP) Co-Chair 2 Andrew Robertson IRI (WCRP) Arun Kumar CPC/NCEP Harry Hendon CAWCR CSIRO/BoM Yuhei Takaya JMA Hai Lin EC Alberto Arribas UKMO June-Yi Lee IPRC Duane Waliser NASA Hyun-Kyung Kim KMA Ben Kirtman IGES/COLA  Liaison Group Carolina Vera WCRP JSC Liaison Richard Graham UKMO CBS12 Jean-Pierre Ceron Meteo-France CCL Barbara Brown SERA/Verification  Consultant David Anderson

17. WWRP Thank You Merci