Caio A. S. Coelho

1
The EUROBRISA operational system

• Caio A. S. Coelho
• Centro de Previsão de Tempo e Estudos Climáticos
  (CPTEC)
• Instituto Nacional de Pesquisas Espaciais (INPE)
• caio_at_cptec.inpe.br

PLAN OF TALK 1. Introduction 2. EUROBRISA
integrated forecasting system 3. Forecasts for
2007-2008 4. Skill of the hindcasts 5. Summary
1st EUROBRISA workshop, Paraty, 17-19 March 2008
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1. Seasonal climate forecasts
Forecasts of climate conditions for the next 3-6
months
DJF







May
Mar
Apr
Nov
Dec
Feb
Jan
0 1 2 3 4 5 6
1-month lead for DJF
Current forecast approaches

• Empirical/statistical models
• Dynamical atmospheric models
• Dynamical coupled (ocean-atmosphere) models

3
2. EUROBRISA integrated forecasting system for
South America

• Combined and calibrated coupled empirical
  precip. forecasts
• Hybrid multi-model probabilistic system

Integrated
Empirical model Predictors Atlantic e Pacific
SST Predictand Precipitation
Hindcast period 1987-2001
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The Empirical model

• Data sources
• SST Reynolds OI v2
• Reynolds et al. (2002)
• Precipitation GPCP v2Adler et al. (2003)

Y
Z
YZ N (M (Z - Zo),T)
Y DJF precipitation Z October sea surface
temp. (SST)
Model uses first three leading Maximum
CovarianceAnalysis (MCA) modes of the matrix YT
Z.
Coelho et al. (2006)
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Empirical forecast DJF 2007/08
First mode (71)



Second mode (7.7)



Issued November 2007

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Conceptual framework
Data Assimilation
Forecast Assimilation
Stephenson et al. (2005)
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Calibration and combination procedure Forecast
Assimilation
Stephenson et al. (2005)
X forecasts (coupled empir.) Y DJF
precipitation
Prior
Likelihood
Matrices
Posterior
Forecast assimilation uses the first three MCA
modes of the matrix YT X.
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Web site launched in Oct 2007 http//www6.cptec.i
npe.br/eurobrisa/
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3. EUROBRISA forecasts for 2007-2008
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Examples of forecast productsProbability of most
likely precip. tercile DJF 2007/08
Empirical
Integrated
ECMWF
UKMO
Issued Nov 2007
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Categorical forecast DJF 2007/08 precip.
ECMWF
Integrated
UKMO
Empirical
Issued Nov 2007
12
Prob. above average precip DJF 2007/08
ECMWF
UKMO
Integrated
Empirical
Issued Nov 2007
13
Prob. precip. in lower tercile DJF 2007/08
ECMWF
UKMO
Integrated
Empirical
Issued Nov 2007
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Obs. SST anomaly Feb 2007
EUROBRISA integrated forecast for AMJ 2007
Issued March 2007
Prob. of most likely precip. tercile ()
Observed precip. tercile
Gerrity score (tercile categories)
Hindcasts 1987-2001
15
Obs. SST anomaly Mar 2007
EUROBRISA integrated forecast for MJJ 2007
Issued April 2007
Prob. of most likely precip. tercile ()
Observed precip. tercile
Gerrity score (tercile categories)
Hindcasts 1987-2001
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Obs. SST anomaly Apr 2007
EUROBRISA integrated forecast for JJA 2007
Issued May 2007
Observed precip. tercile
Prob. of most likely precip. tercile ()
Gerrity score (tercile categories)
Hindcasts 1987-2001
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Obs. SST anomaly May 2007
EUROBRISA integrated forecast for JAS 2007
Issued Jun 2007
Prob. of most likely precip. tercile ()
Observed precip. tercile
Gerrity score (tercile categories)
Hindcasts 1987-2001
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Obs. SST anomaly Jun 2007
EUROBRISA integrated forecast for ASO 2007
Issued Jul 2007
Prob. of most likely precip. tercile ()
Gerrity score (tercile categories)
Observed precip. tercile
Hindcasts 1987-2001
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Obs. SST anomaly Jul 2007
EUROBRISA integrated forecast for SON 2007
Issued Aug 2007
Prob. of most likely precip. tercile ()
Gerrity score (tercile categories)
Observed precip. tercile
Hindcasts 1987-2001
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Obs. SST anomaly Aug 2007
EUROBRISA integrated forecast for OND 2007
Issued Sep 2007
Prob. of most likely precip. tercile ()
Gerrity score (tercile categories)
Observed precip. tercile
Hindcasts 1987-2001
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Obs. SST anomaly Sep 2007
EUROBRISA forecastsfor NDJ 2007/08
Issued Oct 2007
Prob. of most likely precip. tercile ()
Integrated
UKMO
Empirical
ECMWF
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Obs. SST anomaly Oct 2007
EUROBRISA forecastsfor DJF 2007/08
Issued Nov 2007
Prob. of most likely precip. tercile ()
Integrated
UKMO
Empirical
ECMWF
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Obs. SST anomaly Nov 2007
EUROBRISA forecastsfor JFM 2008
Issued Dec 2007
Prob. of most likely precip. tercile ()
Integrated
UKMO
Empirical
ECMWF
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Obs. SST anomaly Dec 2007
EUROBRISA forecastsfor FMA 2008
Issued Jan 2008
Prob. of most likely precip. tercile ()
Integrated
UKMO
Empirical
ECMWF
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Obs. SST anomaly Jan 2008
EUROBRISA forecastsfor MAM 2008
Issued Feb 2008
Prob. of most likely precip. tercile ()
Integrated
UKMO
Empirical
ECMWF
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4. Skill of the hindcasts
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Correlation btw. obs. and fcst. DJF precip. anom.
Examples of verification products
Empirical
Integrated
UKMO
ECMWF

• Hindcast period 1987-2001
• Coupled models with I.C. 1st Nov (1-month lead
  for DJF)
• Empirical model uses Oct SST as predictor for
  DJF precip.
• Integrated forecasts (coupled empirical) with
  forecast assimilation

• Best skill in tropical and southeast South America

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Brier Skill Score (pos. or neg. anomaly) DJF
precipitation
Empirical
Integrated
UKMO
ECMWF

• Hindcast period 1987-2001
• Coupled models with I.C. 1st Nov (1-month lead
  for DJF)
• Empirical model uses Oct SST as predictor for
  DJF precip.
• Integrated forecasts (coupled empirical) with
  forecast assimilation

29
Reliability diagram (pos. or neg. anomaly) DJF
precipitation
Integrated
UKMO
ECMWF
Empirical

• Hindcast period 1987-2001
• Coupled models with I.C. 1st Nov (1-month lead
  for DJF)
• Empirical model uses Oct SST as predictor for
  DJF precip.
• Integrated forecasts (coupled empirical) with
  forecast assimilation

30
ROC curve (pos. or neg. anomaly) DJF
precipitation
Empirical
Integrated
UKMO
ECMWF

• Hindcast period 1987-2001
• Coupled models with I.C. 1st Nov (1-month lead
  for DJF)
• Empirical model uses Oct SST as predictor for
  DJF precip.
• Integrated forecasts (coupled empirical) with
  forecast assimilation

31
ROC skill score (pos. or neg. anomaly) DJF
precipitation
Empirical
Integrated
UKMO
ECMWF

• Hindcast period 1987-2001
• Coupled models with I.C. 1st Nov (1-month lead
  for DJF)
• Empirical model uses Oct SST as predictor for
  DJF precip.
• Integrated forecasts (coupled empirical) with
  forecast assimilation

A is the area under the ROC curve
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Ranked probability skill score (tercile
categories) DJF precipitation
Empirical
Integrated
UKMO
ECMWF

• Hindcast period 1987-2001
• Coupled models with I.C. 1st Nov (1-month lead
  for DJF)
• Empirical model uses Oct SST as predictor for
  DJF precip.
• Integrated forecasts (coupled empirical) with
  forecast assimilation

33
Gerrity score (tercile categories) DJF
precipitation
Empirical
Integrated
UKMO
ECMWF

• Hindcast period 1987-2001
• Coupled models with I.C. 1st Nov (1-month lead
  for DJF)
• Empirical model uses Oct SST as predictor for
  DJF precip.
• Integrated forecasts (coupled empirical) with
  forecast assimilation

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5. Summary

• EUROBRISA integrated forecasting system First
  operational hybrid (empirical-dynamical)
  probabilistic seasonal forecasting system for
  South America
• Current operational system SST-based empirical
  model two dynamical coupled models (ECMWF and
  UKMO)
• Good performance in 2007 over regions where
  forecasts have historically moderate to good
  skill
• Web products include a range of forecast and
  verification products for the EUROBRISA
  integrated forecasting system in addition to
  Meteo-France coupled model forecasts
• Additional information at http//www6.cptec.inpe.b
  r/eurobrisa and in Coelho et al.(2007)-CLIVAR
  Exchanges No 43 (Volume 12 No 4)

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References

• Adler, R.F., G.J. Huffman, A. Chang, R. Ferraro,
  P. Xie, J. Janowiak, B. Rudolf, U. Schneider, S.
  Curtis, D. Bolvin, A. Gruber, J. Susskind, P.
  Arkin (2003), The Version 2 Global Precipitation
  Climatology Project (GPCP) Monthly Precipitation
  Analysis (1979-Present). J. Hydrometeor.,
  4,1147-1167.
• Coelho C.A.S., D. B. Stephenson, F. J.
  Doblas-Reyes, M. Balmaseda and R. Graham, 2007
  Integrated seasonal climate forecasts for South
  America. CLIVAR Exchanges. No.43. Vol. 12, No.
  4, 13-19.
• Coelho C.A.S., D. B. Stephenson, F. J.
  Doblas-Reyes and M. Balmaseda, 2005 From
  multi-model ensemble predictions to
  well-calibrated probability forecasts Seasonal
  rainfall forecasts over South America 1959-2001
  CLIVAR Exchanges. No.32. Vol. 10, No. 1, 14-20.
• Coelho C.A.S., D. B. Stephenson, M. Balmaseda, F.
  J. Doblas-Reyes and G. J. van Oldenborgh, 2006
  Towards an integrated seasonal forecasting
  system for South America.J. Climate., Vol. 19,
  3704-3721.
• Reynolds, R. W., N. A. Rayner, T. M. Smith, D. C.
  Stokes and W. Wang (2002), An improved in situ
  and satellite SST analysis for climate. J.
  Climate, 15, 1609-1625.
• Stephenson, D. B., C.A.S. Coelho, F. J.
  Doblas-Reyes, and M. Balmaseda, 2005
• Forecast Assimilation A Unified Framework for
  the Combination of
• Multi-Model Weather and Climate Predictions.
  Tellus A, Vol. 57, 253-264.