Evaluation of the climate outlook forums' seasonal precipitation forecasts of southeast South America during 1998-2002

The series of 16 Climate Outlook Forums' (COFs') seasonal precipitation forecasts for southeast South America since December 1997 are verified. The COFs' forecasts consist of a probabilistic tercile distribution of precipitation for the upcoming 3 months period, over a domain in South...

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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08998418_v25_n3_p365_Berri
http://hdl.handle.net/20.500.12110/paper_08998418_v25_n3_p365_Berri
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spelling paper:paper_08998418_v25_n3_p365_Berri2023-06-08T15:49:38Z Evaluation of the climate outlook forums' seasonal precipitation forecasts of southeast South America during 1998-2002 Climate variability Seasonal precipitation forecast South America Validation Expert systems Geographical regions Mathematical models Precipitation (meteorology) Probability Random processes Statistical methods Weather forecasting Climate outlook forums (COF) Hit score (HS) Probabilistic tercile distribution Ranked probability skill score (RPSS) Climate change atmospheric modeling long range forecast precipitation (climatology) weather forecasting South America Western Hemisphere World The series of 16 Climate Outlook Forums' (COFs') seasonal precipitation forecasts for southeast South America since December 1997 are verified. The COFs' forecasts consist of a probabilistic tercile distribution of precipitation for the upcoming 3 months period, over a domain in South America between 20 and 40°S, to the east of the Andes Mountains. The COFs' forecast is the result of the consensus agreement between atmosphere model predictions, physically based statistical model predictions, results of diagnostic analysis and published research on climate variability over the region, and expert interpretation of this information in the context of the current situation. The validation is conducted by means of the hit score (HS), which expresses the percentage of forecasts verified in the dominant predicted category, and the ranked probability skill Score (RPSS), which measures the difference between the probability distribution of the forecasts and the observed categories. The HS reveals that over most of the region the categorical agreement is low and close to 33%, which is the result that would be obtained by a three-category random forecast, and only sparse regions achieve a categorical agreement between 40 and 50%. The regions with positive RPSS (i.e. forecasts better than climatology and potentially useful for applications) represent 30% of the total area considered by the COFs. There are significantly large regions with negative RPSS, i.e. forecasts worse than climatology. The result of the COFs' forecasts is compared with that of the IRI Net Assessment forecasts, the only source of physically based seasonal forecasts regularly available at the COFs' discussions. There is general coincidence in the regions with positive and negative skill. Although one might expect the consensus of the COFs' forecasts to improve upon the skill of the IRI forecast, this was not the case during this period. Copyright 2005 Royal Meteorological Society. 2005 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08998418_v25_n3_p365_Berri http://hdl.handle.net/20.500.12110/paper_08998418_v25_n3_p365_Berri
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Climate variability
Seasonal precipitation forecast
South America
Validation
Expert systems
Geographical regions
Mathematical models
Precipitation (meteorology)
Probability
Random processes
Statistical methods
Weather forecasting
Climate outlook forums (COF)
Hit score (HS)
Probabilistic tercile distribution
Ranked probability skill score (RPSS)
Climate change
atmospheric modeling
long range forecast
precipitation (climatology)
weather forecasting
South America
Western Hemisphere
World
spellingShingle Climate variability
Seasonal precipitation forecast
South America
Validation
Expert systems
Geographical regions
Mathematical models
Precipitation (meteorology)
Probability
Random processes
Statistical methods
Weather forecasting
Climate outlook forums (COF)
Hit score (HS)
Probabilistic tercile distribution
Ranked probability skill score (RPSS)
Climate change
atmospheric modeling
long range forecast
precipitation (climatology)
weather forecasting
South America
Western Hemisphere
World
Evaluation of the climate outlook forums' seasonal precipitation forecasts of southeast South America during 1998-2002
topic_facet Climate variability
Seasonal precipitation forecast
South America
Validation
Expert systems
Geographical regions
Mathematical models
Precipitation (meteorology)
Probability
Random processes
Statistical methods
Weather forecasting
Climate outlook forums (COF)
Hit score (HS)
Probabilistic tercile distribution
Ranked probability skill score (RPSS)
Climate change
atmospheric modeling
long range forecast
precipitation (climatology)
weather forecasting
South America
Western Hemisphere
World
description The series of 16 Climate Outlook Forums' (COFs') seasonal precipitation forecasts for southeast South America since December 1997 are verified. The COFs' forecasts consist of a probabilistic tercile distribution of precipitation for the upcoming 3 months period, over a domain in South America between 20 and 40°S, to the east of the Andes Mountains. The COFs' forecast is the result of the consensus agreement between atmosphere model predictions, physically based statistical model predictions, results of diagnostic analysis and published research on climate variability over the region, and expert interpretation of this information in the context of the current situation. The validation is conducted by means of the hit score (HS), which expresses the percentage of forecasts verified in the dominant predicted category, and the ranked probability skill Score (RPSS), which measures the difference between the probability distribution of the forecasts and the observed categories. The HS reveals that over most of the region the categorical agreement is low and close to 33%, which is the result that would be obtained by a three-category random forecast, and only sparse regions achieve a categorical agreement between 40 and 50%. The regions with positive RPSS (i.e. forecasts better than climatology and potentially useful for applications) represent 30% of the total area considered by the COFs. There are significantly large regions with negative RPSS, i.e. forecasts worse than climatology. The result of the COFs' forecasts is compared with that of the IRI Net Assessment forecasts, the only source of physically based seasonal forecasts regularly available at the COFs' discussions. There is general coincidence in the regions with positive and negative skill. Although one might expect the consensus of the COFs' forecasts to improve upon the skill of the IRI forecast, this was not the case during this period. Copyright 2005 Royal Meteorological Society.
title Evaluation of the climate outlook forums' seasonal precipitation forecasts of southeast South America during 1998-2002
title_short Evaluation of the climate outlook forums' seasonal precipitation forecasts of southeast South America during 1998-2002
title_full Evaluation of the climate outlook forums' seasonal precipitation forecasts of southeast South America during 1998-2002
title_fullStr Evaluation of the climate outlook forums' seasonal precipitation forecasts of southeast South America during 1998-2002
title_full_unstemmed Evaluation of the climate outlook forums' seasonal precipitation forecasts of southeast South America during 1998-2002
title_sort evaluation of the climate outlook forums' seasonal precipitation forecasts of southeast south america during 1998-2002
publishDate 2005
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08998418_v25_n3_p365_Berri
http://hdl.handle.net/20.500.12110/paper_08998418_v25_n3_p365_Berri
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