© Crown copyright Met Office WMO CBS operational collection/display of seasonal (and sub-seasonal) forecasts Richard Graham, Met Office Hadley Centre. With acknowledgements to all GPCs, LC- LRFMME, LC-SVSLRF and members of the WMO Expert Team on Extended and Long- range Forecasting (ET-ELRF) WMO/THORPEX/WCRP sub-seasonal to seasonal implementation planning meeting, WMO HQ, Geneva, 2-3 December 2011

© Crown copyright Met Office Content CBS operational seasonal (and monthly) data exchange and products – GPCs, Lead Centres Input on: Intra-seasonal applications Future CBS operational extended-range data exchange (in ET- ELRF terms of reference)

© Crown copyright Met Office WMO CBS coordination of centres producing long-range forecasts: Global Producing Centres (GPCs) 12 WMO-designated GPCs centres adhering to agreed procedures/standards in LRF – forming an integral part of the WMO GDPFS 2 Lead Centres, facilitating user access to GPC products Lead Centre for Long-range Forecast Multi-model Ensembles (LC- LRFMME) – jointly operated by KMA/NOAA NCEP Lead Centre for the Standard Verification System for Long-range Forecasts (LC-SVSLRF) – jointly operated by BoM/MSC Aim of this GDPFS infrastructure: improve access and usability of global LRF products to aid production of regional/national climate services Growing use at RCOFs and NCOFs

© Crown copyright Met Office GPC designation criteria have fixed production cycles and time of issuance; provide an agreed minimum set of long-range forecast products, 2m temp, precipitation, SST (averages of at least 1-month); any lead-time between 0 and 4 months. 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 Centres)

GPC nameCentreSystem Configurati on (ensemble size of forecast) Resolution (atmosphere) Hindcast period used BeijingBeijing Climate CentreCoupled (48)T63/L CPTECCentre for Weather Forecasts and Climate Studies 2-tier (15)T62/L ECMWFEuropean Centre for Medium Range Weather Forecasts Coupled (41)T159/L ExeterMet Office Hadley Centre Coupled (42)1.25°x1.85°/L MelbourneAustralian Bureau of Meteorology Coupled (30)T47/L MontrealMeteorological Service of Canada 2-tier (40)T32/T63/T95/2.0 °x2.0° (4- model combination) SeoulKorean Meteorological Agency 2-tier (20)T106/L TokyoJapan Meteorological Agency Coupled (51)T95/L ToulouseMétéo-FranceCoupled (41)T63/L WashingtonNational Centres for Environmental Prediction Coupled (40)T62/L MoscowHydromet Centre of Russia 2-tier (10)1.1°x1.4°/L PretoriaSouth African Weather Service 2-tier (6)T42/L The 12 WMO- designated GPCs

Data collected/processed/displayed by LC-LRFMME 1-month means for (at least) next 3-months; all ensemble members (forecast and hindcast); Variables: 2m temperature SST Total precipitation MSLP 850 hPa temperature 500 hPa geopotential height Collected every month between 15 th -20 th. Forecast displays updated on LC-LRFMME website ~ th of month. © Crown copyright Met Office

Products Individual GPCs Deterministic (ensemble mean anomalies) Multi-model (deterministic+): ensemble mean anomalies Nino plumes Model consistency (of anomaly sign) multi-model can be user defined Multi-model (probabilistic) Probabilities of tercile categories Subset of GPCs © Crown copyright Met Office

Lead Centre for Long Range Forecast Multi Model Ensemble © Crown copyright Met Office

Seasonal AND monthly products displayed on LC-LRFMME website DecJanFeb DJF GPC Washington Ensemble mean anomalies: pmsl (2011)

GPC products from LC-LRFMME website: DJF 2010/11: ensemble mean pmsl anomaly Exeter ECMWF Toulouse Beijing Washington TokyoMelbourne Seoul Montreal Coupled systems Un-coupled systems Pretoria ‘Dynamic’ user- selectable domain Same available for individual months

Multi-model GPC products from LC-LRFMME website: DJF 2010/11, ensemble mean pmsl anomaly Ensemble mean of 10 GPCs Ensemble mean of 7 GPCs (coupled systems) Ensemble mean of 3 GPCs (un- coupled systems) multi-model subsets produced interactively from LC-LRFMME website Presented at South East Europe Regional Climate Outlook Forum (SEECOF), November mT, precipitation, T850, Z500, SST and for individual calendar month periods

Nino3.4 plumes

GPC model consistency plots: Individual months: number of models with +ve /-ve anomalies Z500T850PMSL Precip 2mTSST Dec 2011

GPC model consistency plots: Individual months: number of models with +ve /-ve anomalies Z500T850PMSL Precip 2mTSST DJF 2011

Probabilistic products with subset of GPC providing hindcasts Dec 2011

Probabilistic products with subset of GPC providing hindcasts DJF 2011

Use at RCOFs: WMO Lead Centre information and final GHACOF consensus, SOND 2010 LC-LRFMME Model consistency Statistical models + Forecaster judgement Final consensus Verification Observed SON anomalies

Summary – global LRF 12 WMO designated GPCs supply seasonal and ‘subseasonal‘ data 2 WMO Lead centres: dealing with standardised display/multi- modelling and forecast validation Deterministic products and probabilistic products In active use by RCCs, RCOFs, NMHSs (~123 registered users, 49 countries – as of early 2011) Probability products will form basis of prediction component of the WMO Global Seasonal Climate Update (GSCU). Key plans (guided by the Expert Team for Extended and Long- range Forecasts) – in line with GFCS vision - include: verification of multi-model products Investigation/development of extended (monthly) range capability investigation/development of multiannual–to-decadal capability (decadal GPCs?)

CSRP: consultation in Africa Type and number of organisations interviewed Ranking of priorities Questionnaire fielded to 9 climate service providers Total of 52 interviews across 8 African countries

Science component (3): Predicting onset timing based on local time of arrival of 20% of long-term seasonal average Average southward progression of rains with ITZC observed modelled Skill of Met Office seasonal forecasts of ‘onset’ timing early onset late onset orange/red = ‘good’ skill Encouraging first results: trial onset forecasts have been provided to Regional Climate Outlook Forums ICPAC, ACMAD and SADC-DMC Example: East Africa short-rains (OND) Michael Vellinga

Predicting onset timing: example Greater Horn of Africa short-rains season 2011 (OND) – prediction from August based on local time of arrival of 20% of long-term seasonal average Probability of early arrival Probability of late arrival Observed time of arrival

Early thoughts on LC-LRFMME operational exchange Strawman proposal for operational exchange: Coordinate research and operational exchanges with operational exchange a subset of research (delayed release) exchange? 2-weekly issues: first, with the release of LC-LRFMME seasonal forecast; second, 2 weeks later; Daily data to ~32 days; small number of essential variables; Products to be period means; 7 GPCs responded so far: 5 basically ‘yes’; 1 ‘too early’: 1 system not operational; Key issue: coordinating release date to get usefully short lead time, different GPCs have different release dates; should release date be fixed day of month or day of week? Some with data policy issues and other reservations (e.g. Timing of products) © Crown copyright Met Office

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