Flow dependence of wintertime subseasonal prediction skill over Europe
Issuing skillful forecasts beyond the typical horizon of weather predictability remains a challenge actively addressed by the scientific community. This study evaluates winter subseasonal reforecasts delivered by the CNRM and ECMWF dynamical systems and identifies that the level of skill for predict...
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ftcopernicus:oai:publications.copernicus.org:wcd95008 2023-05-15T17:33:32+02:00 Flow dependence of wintertime subseasonal prediction skill over Europe Ardilouze, Constantin Specq, Damien Batté, Lauriane Cassou, Christophe 2021-11-04 application/pdf https://doi.org/10.5194/wcd-2-1033-2021 https://wcd.copernicus.org/articles/2/1033/2021/ eng eng doi:10.5194/wcd-2-1033-2021 https://wcd.copernicus.org/articles/2/1033/2021/ eISSN: 2698-4016 Text 2021 ftcopernicus https://doi.org/10.5194/wcd-2-1033-2021 2021-11-08T17:22:29Z Issuing skillful forecasts beyond the typical horizon of weather predictability remains a challenge actively addressed by the scientific community. This study evaluates winter subseasonal reforecasts delivered by the CNRM and ECMWF dynamical systems and identifies that the level of skill for predicting temperature in Europe varies fairly consistently in both systems. In particular, forecasts initialized during positive North Atlantic Oscillation (NAO) phases tend to be more skillful over Europe at week 3 in both systems. Composite analyses performed in an atmospheric reanalysis, a long-term climate simulation and both forecast systems unveil very similar temperature and sea-level pressure patterns 3 weeks after NAO conditions. Furthermore, regressing these fields onto the 3-weeks-prior NAO index in a reanalysis shows consistent patterns over Europe but also other regions of the Northern Hemisphere extratropics, thereby suggesting a lagged teleconnection, related to either the persistence or recurrence of the positive and negative phases of the NAO. This teleconnection, conditioned to the intensity of the initial NAO phase, is well captured by forecast systems. As a result, it is a key mechanism for determining a priori confidence in the skill of wintertime subseasonal forecasts over Europe as well as other parts of the Northern Hemisphere. Text North Atlantic North Atlantic oscillation Copernicus Publications: E-Journals Weather and Climate Dynamics 2 4 1033 1049 |
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Copernicus Publications: E-Journals |
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English |
description |
Issuing skillful forecasts beyond the typical horizon of weather predictability remains a challenge actively addressed by the scientific community. This study evaluates winter subseasonal reforecasts delivered by the CNRM and ECMWF dynamical systems and identifies that the level of skill for predicting temperature in Europe varies fairly consistently in both systems. In particular, forecasts initialized during positive North Atlantic Oscillation (NAO) phases tend to be more skillful over Europe at week 3 in both systems. Composite analyses performed in an atmospheric reanalysis, a long-term climate simulation and both forecast systems unveil very similar temperature and sea-level pressure patterns 3 weeks after NAO conditions. Furthermore, regressing these fields onto the 3-weeks-prior NAO index in a reanalysis shows consistent patterns over Europe but also other regions of the Northern Hemisphere extratropics, thereby suggesting a lagged teleconnection, related to either the persistence or recurrence of the positive and negative phases of the NAO. This teleconnection, conditioned to the intensity of the initial NAO phase, is well captured by forecast systems. As a result, it is a key mechanism for determining a priori confidence in the skill of wintertime subseasonal forecasts over Europe as well as other parts of the Northern Hemisphere. |
format |
Text |
author |
Ardilouze, Constantin Specq, Damien Batté, Lauriane Cassou, Christophe |
spellingShingle |
Ardilouze, Constantin Specq, Damien Batté, Lauriane Cassou, Christophe Flow dependence of wintertime subseasonal prediction skill over Europe |
author_facet |
Ardilouze, Constantin Specq, Damien Batté, Lauriane Cassou, Christophe |
author_sort |
Ardilouze, Constantin |
title |
Flow dependence of wintertime subseasonal prediction skill over Europe |
title_short |
Flow dependence of wintertime subseasonal prediction skill over Europe |
title_full |
Flow dependence of wintertime subseasonal prediction skill over Europe |
title_fullStr |
Flow dependence of wintertime subseasonal prediction skill over Europe |
title_full_unstemmed |
Flow dependence of wintertime subseasonal prediction skill over Europe |
title_sort |
flow dependence of wintertime subseasonal prediction skill over europe |
publishDate |
2021 |
url |
https://doi.org/10.5194/wcd-2-1033-2021 https://wcd.copernicus.org/articles/2/1033/2021/ |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_source |
eISSN: 2698-4016 |
op_relation |
doi:10.5194/wcd-2-1033-2021 https://wcd.copernicus.org/articles/2/1033/2021/ |
op_doi |
https://doi.org/10.5194/wcd-2-1033-2021 |
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Weather and Climate Dynamics |
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2 |
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4 |
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1033 |
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1049 |
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1766132074596532224 |