© Crown copyright Met Office
WMO Lead-centres for verification and archivingRichard Graham (Met Office Hadley Centre) and Won-Tae Yun (KMA) acknowledgements to all GPCs and members of the WMO Expert Team on Extended and Long-range Forecasting (ET-ELRF)
WMO workshop on Sub-seasonal to Seasonal Prediction, Met Office, Exeter, 1-3 December 2010
Context
• Forecasters like to compare output from different models, this is helped by:
• easy access to products;
• same map projections, contour conventions etc;
• digital data for ‘user’ processing.
• Multi-model combinations also important
• Verification diagnostics also easier to use if presented uniformly
• Need for international coordination
ECMWF
JMA
2m temperature forecasts for DJF2010/11
© Crown copyright Met Office
WMO CBS coordination of centres producing long-range forecasts:Global Producing Centres (GPCs)
First step: agree standard forecast and verification output:
• Designate GPCs: centres adhering to agreed procedures/standards in LRF – there are now 12 GPCs, forming an integral part of the WMO GDPFS
Next step: increase coordination
• 2 Lead Centres, facilitating user access to GPC products
• Lead Centre for Long-range Forecast Multi-model Ensembles (LC-LRFMME)
• Lead Centre for the Standard Verification System for Long-range Forecasts (LC-SVSLRF)
• Aim: improve access and usability of global LRF products to aid production of regional/national climate services
© 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 name Centre System Configuration (ensemble size of forecast)
Resolution (atmosphere)
Hindcast period used
Beijing Beijing Climate Centre Coupled (48) T63/L16 1983-2004
CPTEC Centre for Weather Forecasts and Climate Studies
2-tier (15) T62/L28 1979-2001
ECMWF European Centre for Medium Range Weather Forecasts
Coupled (41) T159/L62 1981-2005
Exeter Met Office Hadley Centre
Coupled (42) 1.25°x1.85°/L38 1989-2002
Melbourne Australian Bureau of Meteorology
Coupled (30) T47/L17 1980-2006
Montreal Meteorological Service of Canada
2-tier (40) T32/T63/T95/2.0°x2.0° (4- model combination)
1969-2004
Seoul Korean Meteorological Agency
2-tier (20) T106/L21 1979-2007
Tokyo Japan Meteorological Agency
Coupled (51) T95/L40 1979-2008
Toulouse Météo-France Coupled (41) T63/L91 1979-2007
Washington National Centres for Environmental Prediction
Coupled (40) T62/L64 1981-2004
Moscow Hydromet Centre of Russia
2-tier (10) 1.1°x1.4°/L28 1979-2003
Pretoria South African Weather Service
2-tier (6) T42/L19 1983-2001
The 12 WMO-designated GPCs
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WMO Lead Centre for LRF Multi-model Ensembles (LC-LRFMME)
http://www.wmolc.org/
Jointly operated byKorean Met Agency & NOAA NCEPWon-Tae Yun, Arun Kumar
• 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 (next 3-months only at present)
• generate and display an agreed set of MME products
• distribute GPC data (for those GPCs that allow it)
• promote research into MME techniques
Primary functions:
GPC forecasts for DJF 2010/11: ensemble mean pmsl anomaly (from LC-LRFMME web)
Exeter ECMWF Toulouse
Beijing
Washington
TokyoMelbourne
Seoul Montreal
Coupled systems
Un-coupled systems
Pretoria
‘Dynamic’ user-selectable domain
Multi-model GPC pmsl forecasts, DJF 2010/11from LC-LRFMME website
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), 22-26 November 2010
What about last year?pmsl anomalies: observed & GPC predictions from Nov09 for DJF2009/10
anomaly sign ‘consistency’Observed pmsl anomalies (wrt 61-90)
10-model multi-model EM
Other products/activities
Other variables:
• Nino3.4 region plumes
• 2m temperature; precipitation; 850 hPa temperature; 500hPa height; SST
Methods of multi-model combining:
• Operational: simple equal weights
• Research: skill weighted combination; linear and non-linear methods
Sub-seasonal:
• 1-month means available in addition to 3-month means
Note: ET-ELRF: last meeting recommended pilot projects on potential for monthly-range prediction for (e.g. rains onset)
© Crown copyright Met Office
Priority prediction needs Africa: rainfallDFID-Hadley Climate Science Research Partnership
• Poll of 9 African Regional Centres and National Meteorological Services • Highest priority: predictions of the temporal distribution of seasonal rainfall (e.g. onset,
duration, dry spells)• Less clear at what lead-time onset prediction is needed to be useful
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No
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tes Rank 1
Rank 2
Rank 3
Rank 4
Question: what next beyond standard 3-month means and terciles?
Lead Centre for Standard Verification of Long-range forecasts (LC-SVSLRF)
• repository of global SVSLRF scores for GPC forecasts
• Core of SVS: 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
http://www.bom.gov.au/wmo/lrfvs/
Jointly operated byBureau of Met. BoM) & Met. Service of Canada (MSC)David Jones, Normand Gagnon
Examples of submitted data http://www.bom.gov.au/cgi-bin/climate/wmo.cgi
ROC curvesROC score maps
Reliability/sharpness diagrams
Courtesy: David Jones (BoM)
Use of Lead Centre products at African Regional Climate Outlook Forums (RCOFs)
GPC forecasts for E. Africa ‘short-rains’ SON 2010: ensemble mean rainfall anomaly
Exeter ECMWF Toulouse
Beijing
Washington
TokyoMelbourne
SeoulMoscow Montreal
Coupled systems
Un-coupled systems
Sample verification: ROC scores for SON precipitation, 1-month lead
ToulouseWashington TokyoMelbourne
above
below
0.6
WMO Lead Centre information and final consensus, SON 2010
Ensemble mean of 10 GPCs
Ensemble mean of 7 GPCs (coupled systems)
Ensemble mean of 3 GPCs (un-coupled systems)
Model consistency
Forecaster judgement
Final consensus
Verification
WMO Lead Centres in context of GFCS
GPCs: role in the Climate Services Information System (CSIS)
GPCs and their
LCs
Other Centres
Monitoring Centres
obs/research
users
GFCS
CSIS
WMO Global Seasonal Climate Updates (GSCUs)
• International consensus on global-scale seasonal monitoring and outlook (will extend the WMO El Niño/La Niña updates);
• Other climate indices (Indian Ocean Dipole, NAO)
• Temperature, precipitation
• Intended users: RCCs, RCOFs, NMHSs, but also ‘globally acting users’ (e.g. UN, Red Cross);
• Scoping meeting and first meeting of GSCU Task Team took place 12-15 October 2010;
• identified work needed before Pilot Phase can be begin
• requirements of GSCUs on the Lead Centres are feeding into work plans, e.g.:
• probability forecast products, extension of forecast range
• verification of the multi-model products
Summary
• WMO CBS (working with CCl) has designated GPCs and associated Lead Centres for multi-modelling and verification - strengthening coordination of LRF
• Forecast and verification products are available to RCCs /NMHSs / RCOFs - active use is being made
• Lead Centres will play a key role in WMO Global Seasonal Climate Updates (monitoring and outlook) – part of GFCS vision.
• Key plans for the WMO Lead Centres (guided by the Expert Team for Extended and Long-range Forecasts) include:
• development of probability forecast products
• extension prediction range (to ~6 months)
• verification of multi-model products
• possible centralisation of the verification process
• Issue of length of hindcast – but also of consistency of choice of the hindcast period across the GPCs
Thank you! Any questions?