1. WWRP The Sub-seasonal to Seasonal (S2S) Prediction Project Co-chairs: Frédéric Vitart (ECMWF) Andrew Robertson (IRI) 1 “Bridging the gap between weather and climate” Arun Kumar Climate Prediction Center, NOAA

2. WWRP Chronology MonthMilestones Nov 2009CAS recommends WCRP, WWRP and THORPEX to set up S2S Dec 2010WWRP-WCRP-THORPEX workshop in Exeter Sept. 2011Formation of the S2S planning group Dec. 2011First S2S planning group meeting in Geneva June 2012Approval of S2S though WMO EC Feb. 2013Second S2S planning group meeting in Exeter March 2013Final version of implementation plan Nov. 2013Opening ceremony of the ICO and S2S launch workshop in Jeju Island, Korea Feb. 2014S2S workshop at NCEP First S2S steering group meeting 2

3. WWRP  Implementation plan finalized & printed (http://www.wmo.int/pages/prog/arep/wwrp/new/S2S_project_main_page.html)http://www.wmo.int/pages/prog/arep/wwrp/new/S2S_project_main_page.html  5-year project, started in Nov 2013.  Project office: KMA will host the project office in Jeju island. S2S project 3

4. WWRP S2S Project Objectives  “To improve forecast skill and understanding on the sub- seasonal to seasonal timescale with special emphasis on high-impact weather events”  “To promote the initiative’s uptake by operational centres and exploitation by the applications community”  “To capitalize on the expertise of the weather and climate research communities to address issues of importance to the Global Framework for Climate Services” The project will focus on the forecast range between 2 weeks and a season 4

5. WWRP Time- range Resol.Ens. SizeFreq.HcstsHcst lengthHcst FreqHcst Size ECMWFD 0-32T639/319L62512/weekOn the flyPast 18yweekly5 UKMOD 0-60N96L854dailyOn the fly1989-20034/month3 NCEPD 0-60N126L6416dailyFix1999-2010daily4 ECD 0-350.6x0.6L4021weeklyOn the flyPast 15yweekly4 CAWCRD 0-120T47L1733weeklyFix1989-20103/month33 JMAD 0-34T159L6050weeklyFix1979-20093/month5 KMAD 0-30T106L21203/monthFix1979-20103/month10 CMAD 0-45T63L16406/monthFix1982-nowmonthly48 Met.FrD 0-60T63L9141monthlyFix1981-2005monthly11 SAWSD 0-60T42L196monthlyFix1981-2001monthly6 HMCRD 0-601.1x1.4 L2810monthlyFix1979-2003monthly10 Sub-seasonal real-time Operational Forecasts 5

6. WWRP  Use TIGGE protocol (GRIB2) for archiving the data. The data should also be available in NetCDF for the WCRP community  Archive daily means of real-time forecasts + hindcasts. – Real-time forecasts 3 weeks behind real-time – Hindcasts depending on centre (nonuniform) – Common 1.5x1.5 degree ERA-interim grid – Update frequency depending on centre  Variables archived: most of TIGGE variables + ocean variables and stratospheric levels + soil moisture/temperature  ECMWF will be a main archiving centre. UKMO will archive a subset of the data (Climate Cloud)  Archiving in the ECMWF server will start in 2014. S2S Database 6

7. WWRP S2S Project Structure 7

8. WWRP S2S Subprojects  Monsoons – e.g., predicting the timing of monsoon onsets, and active/break phases, all monsoons  MJO – Passage over the Maritime Continent and its interaction with the diurnal cycle of rainfall over islands (w/MJO-TF/GEWEX GASS); air-sea interaction  Africa – link to CBS & SERA; weather-within-climate; rainfed agriculture; capacity building  Extreme Weather – Predictability of extreme events (heat/cold waves, drought, tropical cyclones..) – develop a metrics – case studies  Verification – Recommended set of metrics & datasets for verifying S2S forecasts; provide guidance on verification topics to be researched, including methods for probabilistic predictions. 8

9. WWRP Upcoming Conferences Education outreach  WWRP Open Science Conference – 16-21 August 2014, Montreal, Canada: S2S session at the WWOSC : Submission deadline: 24 February 2014 Education:  A proposal to ICTP for a 2 week training course in 2015 for scientists from developing countries.  Explore the possibility to organize a training course with APCC/KMA. 9

10. WWRP Summary  Sub-seasonal to seasonal is a very important time range which links weather and climate communities  S2S is one of the three follow-on projects to THORPEX  What can S2S do for us:  It provides a framework to facilitate international collaboration (S2S database, workshops, coordinated experiments..)  It can help influence research priorities of funding agencies  Training and promotion of early career scientists 10

11. WWRP The S2S Steering Group & Liasion  Frederic Vitart (co-chair)  Andrew Robertson (co-chair)  Arun Kumar  Harry Hendon  Duane Waliser  Yuhei Takaya  Hai Lin  Alberto Arribas  June-Yi Lee  Ben Kirtman International Coordination Office: NIMR, Republic of Korea 11  In-Sik Kang(WCRP_JSC)  Richard Graham(CBS)  Jean-Pierre Ceron(CCL)  Caio Coelho(CPTEC)  Steve Woolnough(GEWEX/GASS)  Bart van den Hurk(GEWEX/GLASS)  Joanne Robbins(SERA)