Dynamics of forecast‐error growth along cut‐off Sanchez and its consequence for the prediction of a high‐impact weather event over southern France
Abstract The representation of a high‐impact weather (HIW) event over southern France is evaluated in Météo‐France forecasts, and the sensitivity of the HIW forecast to the upstream upper‐level flow and the Mediterranean and North Atlantic humidity structure prior to the event is quantified. The eve...
Published in: | Quarterly Journal of the Royal Meteorological Society |
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crwiley:10.1002/qj.4127 2024-09-15T18:22:03+00:00 Dynamics of forecast‐error growth along cut‐off Sanchez and its consequence for the prediction of a high‐impact weather event over southern France Binder, Hanin Rivière, Gwendal Arbogast, Philippe Maynard, Karine Bosser, Pierre Joly, Bruno Labadie, Carole Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung Agence Nationale de la Recherche 2021 http://dx.doi.org/10.1002/qj.4127 https://onlinelibrary.wiley.com/doi/pdf/10.1002/qj.4127 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/qj.4127 https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/qj.4127 en eng Wiley http://creativecommons.org/licenses/by/4.0/ Quarterly Journal of the Royal Meteorological Society volume 147, issue 739, page 3263-3285 ISSN 0035-9009 1477-870X journal-article 2021 crwiley https://doi.org/10.1002/qj.4127 2024-08-01T04:20:49Z Abstract The representation of a high‐impact weather (HIW) event over southern France is evaluated in Météo‐France forecasts, and the sensitivity of the HIW forecast to the upstream upper‐level flow and the Mediterranean and North Atlantic humidity structure prior to the event is quantified. The event occurred in October 2016 during the international field experiment NAWDEX. The approach of an upper‐level potential vorticity (PV) cut‐off, referred to as cut‐off , triggered extreme precipitation over southern France. Many 2‐ to 7‐day ensemble forecasts predicted the maximum of the extreme precipitation and the location of the upper‐level PV cut‐off too far to the east. This eastward shift primarily resulted from an underestimation of the cut‐off intensity two days before the HIW and the subsequent downstream propagation and amplification of these errors in the vicinity of . Improving the representation of the cut‐off two days before the event significantly improved the forecast quality. Another error source were inaccuracies in the moisture structure in the eastern North Atlantic. Specifically, an underestimation of the moisture in the warm conveyor belt inflow led to errors in the low‐ and upper‐level circulation that eventually contributed to the eastward shift of the HIW two days later. Corrections in the eastern North Atlantic humidity structure further improved the forecast quality. On the other hand, corrections in the Mediterranean humidity structure had only a small impact on the accuracy of the forecast. The findings illustrate the importance of downstream error propagation and moist diabatic processes for the prediction of extreme weather over Europe, and demonstrate how targeted changes in the PV and humidity field a few days in advance can improve the quality of the forecasts. Article in Journal/Newspaper North Atlantic Wiley Online Library Quarterly Journal of the Royal Meteorological Society 147 739 3263 3285 |
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Open Polar |
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Wiley Online Library |
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crwiley |
language |
English |
description |
Abstract The representation of a high‐impact weather (HIW) event over southern France is evaluated in Météo‐France forecasts, and the sensitivity of the HIW forecast to the upstream upper‐level flow and the Mediterranean and North Atlantic humidity structure prior to the event is quantified. The event occurred in October 2016 during the international field experiment NAWDEX. The approach of an upper‐level potential vorticity (PV) cut‐off, referred to as cut‐off , triggered extreme precipitation over southern France. Many 2‐ to 7‐day ensemble forecasts predicted the maximum of the extreme precipitation and the location of the upper‐level PV cut‐off too far to the east. This eastward shift primarily resulted from an underestimation of the cut‐off intensity two days before the HIW and the subsequent downstream propagation and amplification of these errors in the vicinity of . Improving the representation of the cut‐off two days before the event significantly improved the forecast quality. Another error source were inaccuracies in the moisture structure in the eastern North Atlantic. Specifically, an underestimation of the moisture in the warm conveyor belt inflow led to errors in the low‐ and upper‐level circulation that eventually contributed to the eastward shift of the HIW two days later. Corrections in the eastern North Atlantic humidity structure further improved the forecast quality. On the other hand, corrections in the Mediterranean humidity structure had only a small impact on the accuracy of the forecast. The findings illustrate the importance of downstream error propagation and moist diabatic processes for the prediction of extreme weather over Europe, and demonstrate how targeted changes in the PV and humidity field a few days in advance can improve the quality of the forecasts. |
author2 |
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung Agence Nationale de la Recherche |
format |
Article in Journal/Newspaper |
author |
Binder, Hanin Rivière, Gwendal Arbogast, Philippe Maynard, Karine Bosser, Pierre Joly, Bruno Labadie, Carole |
spellingShingle |
Binder, Hanin Rivière, Gwendal Arbogast, Philippe Maynard, Karine Bosser, Pierre Joly, Bruno Labadie, Carole Dynamics of forecast‐error growth along cut‐off Sanchez and its consequence for the prediction of a high‐impact weather event over southern France |
author_facet |
Binder, Hanin Rivière, Gwendal Arbogast, Philippe Maynard, Karine Bosser, Pierre Joly, Bruno Labadie, Carole |
author_sort |
Binder, Hanin |
title |
Dynamics of forecast‐error growth along cut‐off Sanchez and its consequence for the prediction of a high‐impact weather event over southern France |
title_short |
Dynamics of forecast‐error growth along cut‐off Sanchez and its consequence for the prediction of a high‐impact weather event over southern France |
title_full |
Dynamics of forecast‐error growth along cut‐off Sanchez and its consequence for the prediction of a high‐impact weather event over southern France |
title_fullStr |
Dynamics of forecast‐error growth along cut‐off Sanchez and its consequence for the prediction of a high‐impact weather event over southern France |
title_full_unstemmed |
Dynamics of forecast‐error growth along cut‐off Sanchez and its consequence for the prediction of a high‐impact weather event over southern France |
title_sort |
dynamics of forecast‐error growth along cut‐off sanchez and its consequence for the prediction of a high‐impact weather event over southern france |
publisher |
Wiley |
publishDate |
2021 |
url |
http://dx.doi.org/10.1002/qj.4127 https://onlinelibrary.wiley.com/doi/pdf/10.1002/qj.4127 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/qj.4127 https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/qj.4127 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Quarterly Journal of the Royal Meteorological Society volume 147, issue 739, page 3263-3285 ISSN 0035-9009 1477-870X |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.1002/qj.4127 |
container_title |
Quarterly Journal of the Royal Meteorological Society |
container_volume |
147 |
container_issue |
739 |
container_start_page |
3263 |
op_container_end_page |
3285 |
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1810461348333617152 |