© Crown copyright Met Office New perspectives for GPCs, their role in the GFCS and a proposed contribution to a ‘World Climate Watch’ Richard Graham, Met Office Hadley Centre, acknowledgements to colleagues on CBS ET-ELRF, R. Kolli (WMO), Doug Smith (Met Office) WMO CCl Technical Conference on Changing Climate and Demands for Climate Services for Sustainable Development Antalya, Turkey, February 2010

© Crown copyright Met Office Content Global Producing Centres for long-range forecasts (GPCs) and two associated Lead Centres Introduction Status, example seasonal forecast products, use at Regional Climate Outlook Forums Next steps Potential expansion of GPC activities – consistent with the Global Framework for Climate Services

© Crown copyright Met Office GPCs and associated Lead Centres WMO CBS coordination of centres making dynamical global long-range (seasonal) forecasts (LRF) guided by ET on Extended and Long-range Forecasts 11 WMO-designated GPCs adhering to agreed procedures/standards in LRF – integral part of the WMO GDPFS 2 Lead Centres, facilitating user access to GPC products Aim: improved access and usability of global LRF products for use by RCCs, RCOFs and NMHSs to aid production of regional/national climate services

GPCs: role in the Climate Services Information System (CSIS) GPCs and their LCs Other Centres Data Centres obs/research users GFCS CSIS

© Crown copyright Met Office GPC designation criteria have fixed production cycles and time of issuance; provide an agreed set of long-range forecast products, 2m temp, precip, T850, Z500, SST; provide an agreed set of forecast quality measures (WMO Standard Verification System for LRF); provide up-to-date information on forecast methodology used; make products accessible to users (through website and Lead Centre)

© Crown copyright Met Office The GPCs (designated 2006 & 2009) GPCSystem Config. (ens)Reso. (Atm.)Hindcast Period Beijing, BCCCoupled (48)T63/L ECMWFCoupled (41)T159/L Exeter, Met OfficeCoupled (42)1.25x1.85/L Melbourne, BoMCoupled (30)T47/L Montreal, CMC2-tier (40)T32/T63/T Seoul, KMA2-tier (20)T106/L Tokyo, JMA2-tier (51)T63/L Toulouse, Météo-FrCoupled (41)T63/L Washington, NCEPCoupled (40)T62/L Moscow, HMC2-tier (10)1.1x1.4/L Pretoria, SAWS2-tier--

GPCs and other prediction centres & multi-models IRI ENSO plume APCN-MME EUROSIP: ECMWF, Met Office, Météo-France

© Crown copyright Met Office WMO Lead Centre for LRF Multi- model Ensembles (LC-LRFMME) Jointly operated by Korean Met Agency & NOAA NCEP collect LRF data from GPCs core data: monthly pre-calculated anomalies (EM + members) active additional data: hindcast and forecast started but not active display GPC forecasts in standard formats generate and display an agreed set of MME products distribute GPC data (for those GPCs that allow it) research into MME techniques and products Primary functions:

Negative AO, DJF 2009/10 pmsl anomalies: observed & and GPC predictions from Nov09 (ensemble mean) 1-tier 2-tier Observed pmsl anomalies 1 Dec – 10 Feb (wrt 61-90) From LC-LRFMME website

Negative AO, winter 2009/10 pmsl anomalies: observed & GPC predictions from Nov09 anomaly sign ‘consistency’ Observed pmsl anomalies 1 Dec – 10 Feb (wrt 61-90) 10-model multi-model EM 1-tier multi-model (6)2-tier multi-model (4) multi-model subsets produced interactively from LC-LRFMME website

© Crown copyright Met Office February 2009 for Horn of Africa March- April-May (MAM) ‘long’ rains: consensus prediction multi-model prediction from 10 GPCs (LC-LRFMME) Regional Climate Outlook Forum consensus Observed precipitation anomalies category probabilities ICPAC and GHA country climatologists GPC products from the LC-LRFMME and LC-SVSLRF now introduced at: - GHACOF 23 (MAM ‘09) - FOCRAII (JJA ‘09) - PRESAO 12 (JAS ‘09) - GHACOF 24 (SOND ‘09)

Lead Centre for Standard Verification of Long-range forecasts (LC-SVSLRF) repository of global SVSLRF scores for GPC forecasts ROC maps and diagrams, reliability diagrams, MSSS documentation on verification scores (Attachment II-8 of the WMO manual on the GDPFS) observation datasets for verification, and code for calculating the SVSLRF scores Jointly operated by Bureau of Met. BoM) & Met. Service of Canada (MSC)

© Crown copyright Met Office Example ROC scores for lower tercile, from LC-SVSLRF: Greater Horn of Africa ToulouseWashingtonExeter Green = ROC score >0.55 MAM SON

© Crown copyright Met Office Next steps… GPC and Lead Centre products are ‘up and running’, however still much work to do…. phase 2 exchange: hindcast data, probability products widen range of products additional climate indices (e.g. IOD, NAO) verification of GPC multi-model products encourage increasing standardisation GPC hindcast periods, datasets used for HC verification

© Crown copyright Met Office Potential expansion of GPC roles: 1.WMO Global Seasonal Climate Updates (the GFCS ‘expects’…, the required monitoring and prediction tools exist) Topic for discussion session…

Vision (courtesy Dr. Kolli, WMO) A global seasonal climate update is issued jointly by experts of the GPCs, related Lead Centres and global data/monitoring centres, with input from regions (RCCs, RCOFs, NMHSs) Issued a few days ahead of DJF, MAM, JJA, SON. Two components: monitoring: summary of current and recent climate state prediction: major climate indices (e.g., ENSO, North Atlantic Oscillation, Indian Ocean Dipole, etc.) - likely impacts on large-scale temperature and precipitation patterns. Discussion of prediction uncertainties.

Global Seasonal Climate Updates: motivation The GFCS should develop the capability to deliver an authoritative consensus on the global outlook for next season. The Updates would be an extension of the existing WMO El Niño/La Niña updates. Iteration of the Update will help to set the large-scale (dynamical forecast) context for elaboration on regional and national scales (by RCCs, RCOFs, NMHSs) The Updates will inform users with global remit (e.g. Aid Agencies), promoting services (CSIS) and priming further consultation with RCCs etc.

Some challenges Temperature and precipitation updates intrinsically more problematic than ENSO updates Harmonising with regional/national forecasts may not be straightforward (e.g. timing issues) Further development of LC-LRFMME products and skill assessments needed. Product format? Graphics or text based? NB: translation of probabilities into text can easily lead to miscommunication – recent Met Office experience endorses this!

Way forward Proposed CCl/CBS inter-commission expert meeting to scope Global Seasonal Climate Updates 2 nd quarter 2010 – venue to be decided Objectives: define methodology define content/format develop implementation plan identify lead coordinators

© Crown copyright Met Office Potential expansion of GPC roles: 2. Inter-annual to decadal prediction: examples from Met Office decadal prediction system (DePreSys)

Inter-annual to decadal prediction Strong user requirement for inter-annual to decadal predictions for planning and adaptation On these timescales changes due to natural climate variability and GHG emissions can be of similar order – need initialised predictions Some GPCs are developing initialised decadal predictions, seamless with seasonal predictions. Case for global-average temperature proven (Smith et al., 2007), very encouraging evidence for regional skill. CMIP5 will begin an international comparison of decadal prediction systems It is timely to plan coordination/exchange of decadal predictions among centres with capability, to begin to shape infrastructure for this component in the CSIS of the GFCS.

Assessment of DePreSys ensemble-mean forecast from June 2005 Temp. anomalies (wrt ) for the (~3.5yr) period June 2005 to Nov 2008

Impact of initialisation on hindcast skill 5-year mean (JJASON) surface temp 15°x15° averaging DePreSys-NoAssim correlationDePreSys anomaly correlation HadCM3 9 member perturbed physics ensemble Starting every Nov from 1960 to 2005

DePreSys Skill of DePreSys annual precipitation forecasts: Anomaly correlation, November hindcasts , 35°x35° averaging (verification = GPCP) NoAssim Year 1 Year 2

Summary WMO CBS (working with CCl) has established GPCs and associated Lead Centres for multi-modelling and verification - strengthening infrastructure for LRF Forecast and verification products are available to RCCs / NMHSs / RCOFs - active use is being made at RCOFs A significant new contribution is proposed: WMO Global Seasonal Climate Updates (monitoring and outlook) - responds to user demand, developing GPC infrastructure, and GFCS vision. It is now timely to plan an experimental coordination/exchange of decadal predictions, along lines defined for LRF, to begin to shape this timescale within the CSIS

Thank you! Any questions?

Rainfall anomalies JJA 2009 Observed precip anomalies JJA 2009 (wrt 79-00) CAMS_OPI 10-model multi-model EM