© Crown copyright Met Office WCRP Working Group on Seasonal to Interannual Prediction Adam Scaife (Met Office) & Francisco Doblas-Reyes (IC3) (WGSIP co-chairs)

Near term climate predictions for GFCS: WGSIP with WMO Global Producing Centres See also the WMO Lead Centre for long range forecast multi-model ensembles: WCRP Grand Challenge #1

WMO Global Producing Centres See also the WMO Lead Centre for long range forecast multi-model ensembles:

(1 st ) International workshop on seasonal to decadal prediction Toulouse May 13-16, special thanks to George Boer and Laurent Terray

CIMA CHFP Data Server

CHFP database “CMIP for seasonal forecasting”

NAO prediction skill Skill of NAO forecasts increases with ensemble size Signals to noise is small so large ensembles are needed! All models show some skill and the predictability of the NAO is much higher than in previous operational systems

© Crown copyright Met Office Stratosphere Historical Forecast Project a WGSIP-SPARC project Amy Butler, Adam Scaife, Alexander Lawes, Natalia Calvo, Andrew Charlton-Perez + WGSIP members High Top Hindcasts Parallel to WGSIP-CHFP Extended models Initialising extra atmosphere, better represented stratosphere Integrations 4 month lead times (1 st November and 1st May start dates) 2 seasons (DJF and JJA) Case study years: 1989 onwards At least 6 members per year, preferably more

Slides from Amy et al Strat-Trop links Amy Butler

Land surface: Impact of initialisation Revisiting GLACE2: Difference in the correlation of the ensemble-mean near- surface temperature from two experiments, one using a realistic and another a climatological land-surface initialisation. Results for EC-Earth2.3 started every May over with ERAInt and ORAS4 initial conditions and a sea-ice reconstruction. C. Prodhomme (IC3) May (first forecast month) JJA (forecast months 2-4)

J. García-Serrano (IPSL) IceHFP: Predictions of DJF NAO with EC-Earth2.3 started in November over with ERAInt and ORAS4 initial conditions. Two sets, one initialised with realistic (top) and one with climatological (bottom) sea-ice initial conditions. Sea ice: Impact of initialisation

WGSIPWGCM DCPP Decadal Prediction

Decadal Predictions CMIP5 Protocol CMIP-WGCM-WGSIP oversee this framework Part of our discussions is to think about ‘What next?’ Working with Veronika Eyring, George Boer et al on CMIP6

CMIP5 decadal predictions Predictions (yr 2-5) from 6 CMIP5 systems Initialized solid, uninitialised dashed Global-mean T and Atlantic multi-decadal variability Correlations and RMSE below BUT Outstanding issues with protocol See proposal for a joint WGCM/WGSIP/CLIVAR for CMIP6…. Doblas-Reyes et al. (2013) Forecast time

Real Time Decadal Forecast Exchange Doug Smith, Adam Scaife and the decadal prediction community…. 15th session of the WMO Commission for Climatology recommended action to start the coordination and exchange of decadal predictions Proposal went out to various groups to exchange decadal prediction information research exercise – we can learn a lot from this prevent over-confidence from a single model equal access, ownership and recognition Uni. Tokyo – Kimoto Masahide, MRI – Masayoshi Ishii, SMHI – Klaus Wyser,Colin Jones, KNMI – Wilco Hazeleger, IC3 – Francisco Doblas- Reyes, Virginie Guemas, MPI – Daniela Matei, Wolfgang Muller, Holger Pohlman, CCCMA – George Boer, Bill Merryfield, UKMO-Hadley – Doug Smith, Adam Scaife, READING UNI – Ed Hawkins, NRL – Judith Lean, David Rind, CERFACS – Christophe Cassou, IPSL – Juliette Mignot

Real Time Decadal Forecasts: relative to ForecastsEffect of initialisation Smith et al, Clim. Dyn., 2012

Decadal Prediction for CMIP6: a proposal WGSIP, WGCM & CLIVAR developing decadal prediction expts for CMIP6 via Decadal Climate Prediction Panel (George Boer)

WGSIP activities summary Growing number of seasonal hindcasts in the CHFP database (CMIP for seasonal) Exciting results for extratropical winter predictability and a clear role for the stratosphere Increasing interest in the initialisation of sea ice, and revisiting land-surface initialisation Decadal hindcasts provided to CMIP5 and analyses appearing in literature Real time decadal predictions being exchanged (Smith et al 2012) A draft decadal prediction protocol for CMIP6 is being developed jointly by WGSIP/WGCM/CLIVAR following agreement amongst these groups via the Decadal Climate Prediction Panel

Links to S2S Teleconnections between tropics and extratropics Drift/initial shock and verification within the first month Data dissemination Links to GFCS