Predictive skill for atmospheric rivers in the western Iberian Peninsula
A large fraction of extreme precipitation and flood events across western Europe are triggered by atmospheric rivers (ARs). The association between ARs and extreme precipitation days over the Iberian Peninsula has been well documented for western river basins. Since ARs are often associated with hig...
Published in: | Natural Hazards and Earth System Sciences |
---|---|
Main Authors: | , , , |
Format: | Text |
Language: | English |
Published: |
2020
|
Subjects: | |
Online Access: | https://doi.org/10.5194/nhess-20-877-2020 https://nhess.copernicus.org/articles/20/877/2020/ |
id |
ftcopernicus:oai:publications.copernicus.org:nhess80460 |
---|---|
record_format |
openpolar |
spelling |
ftcopernicus:oai:publications.copernicus.org:nhess80460 2023-05-15T17:35:30+02:00 Predictive skill for atmospheric rivers in the western Iberian Peninsula Ramos, Alexandre M. Sousa, Pedro M. Dutra, Emanuel Trigo, Ricardo M. 2020-03-30 application/pdf https://doi.org/10.5194/nhess-20-877-2020 https://nhess.copernicus.org/articles/20/877/2020/ eng eng doi:10.5194/nhess-20-877-2020 https://nhess.copernicus.org/articles/20/877/2020/ eISSN: 1684-9981 Text 2020 ftcopernicus https://doi.org/10.5194/nhess-20-877-2020 2020-07-20T16:22:20Z A large fraction of extreme precipitation and flood events across western Europe are triggered by atmospheric rivers (ARs). The association between ARs and extreme precipitation days over the Iberian Peninsula has been well documented for western river basins. Since ARs are often associated with high impact weather, it is important to study their medium-range predictability. Here we perform such an assessment using the ECMWF ensemble forecasts up to 15 d for events where ARs made landfall in the western Iberian Peninsula during the winters spanning between 2012–2013 and 2015–2016. Vertically integrated horizontal water vapor transport (IVT) and precipitation from the 51 ensemble members of the ECMWF Integrated Forecasting System (IFS) ensemble (ENS) were processed over a domain including western Europe and the contiguous North Atlantic Ocean. Metrics concerning AR location, intensity, and orientation were computed, in order to compare the predictive skill (for different prediction lead times) of IVT and precipitation. We considered several regional boxes over western Iberia, where the presence of ARs is detected in analysis/forecasts, enabling the construction of contingency tables and probabilistic evaluation for further objective verification of forecast accuracy. Our results indicate that the ensemble forecasts have skill in detecting upcoming AR events, which can be particularly useful to better predict potential hydrometeorological extremes. We also characterized how the ENS dispersion and confidence curves change with increasing forecast lead times for each sub-domain. The probabilistic evaluation, using receiver operating characteristic (ROC) analysis, shows that for short lead times precipitation forecasts are more accurate than IVT forecasts, while for longer lead times this reverses ( ∼10 d). Furthermore, we show that this reversal occurs for shorter lead times in areas where the AR contribution is more relevant for winter precipitation totals (e.g., northwestern Iberia). Text North Atlantic Copernicus Publications: E-Journals Western River ENVELOPE(-107.169,-107.169,66.367,66.367) Natural Hazards and Earth System Sciences 20 3 877 888 |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
A large fraction of extreme precipitation and flood events across western Europe are triggered by atmospheric rivers (ARs). The association between ARs and extreme precipitation days over the Iberian Peninsula has been well documented for western river basins. Since ARs are often associated with high impact weather, it is important to study their medium-range predictability. Here we perform such an assessment using the ECMWF ensemble forecasts up to 15 d for events where ARs made landfall in the western Iberian Peninsula during the winters spanning between 2012–2013 and 2015–2016. Vertically integrated horizontal water vapor transport (IVT) and precipitation from the 51 ensemble members of the ECMWF Integrated Forecasting System (IFS) ensemble (ENS) were processed over a domain including western Europe and the contiguous North Atlantic Ocean. Metrics concerning AR location, intensity, and orientation were computed, in order to compare the predictive skill (for different prediction lead times) of IVT and precipitation. We considered several regional boxes over western Iberia, where the presence of ARs is detected in analysis/forecasts, enabling the construction of contingency tables and probabilistic evaluation for further objective verification of forecast accuracy. Our results indicate that the ensemble forecasts have skill in detecting upcoming AR events, which can be particularly useful to better predict potential hydrometeorological extremes. We also characterized how the ENS dispersion and confidence curves change with increasing forecast lead times for each sub-domain. The probabilistic evaluation, using receiver operating characteristic (ROC) analysis, shows that for short lead times precipitation forecasts are more accurate than IVT forecasts, while for longer lead times this reverses ( ∼10 d). Furthermore, we show that this reversal occurs for shorter lead times in areas where the AR contribution is more relevant for winter precipitation totals (e.g., northwestern Iberia). |
format |
Text |
author |
Ramos, Alexandre M. Sousa, Pedro M. Dutra, Emanuel Trigo, Ricardo M. |
spellingShingle |
Ramos, Alexandre M. Sousa, Pedro M. Dutra, Emanuel Trigo, Ricardo M. Predictive skill for atmospheric rivers in the western Iberian Peninsula |
author_facet |
Ramos, Alexandre M. Sousa, Pedro M. Dutra, Emanuel Trigo, Ricardo M. |
author_sort |
Ramos, Alexandre M. |
title |
Predictive skill for atmospheric rivers in the western Iberian Peninsula |
title_short |
Predictive skill for atmospheric rivers in the western Iberian Peninsula |
title_full |
Predictive skill for atmospheric rivers in the western Iberian Peninsula |
title_fullStr |
Predictive skill for atmospheric rivers in the western Iberian Peninsula |
title_full_unstemmed |
Predictive skill for atmospheric rivers in the western Iberian Peninsula |
title_sort |
predictive skill for atmospheric rivers in the western iberian peninsula |
publishDate |
2020 |
url |
https://doi.org/10.5194/nhess-20-877-2020 https://nhess.copernicus.org/articles/20/877/2020/ |
long_lat |
ENVELOPE(-107.169,-107.169,66.367,66.367) |
geographic |
Western River |
geographic_facet |
Western River |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
eISSN: 1684-9981 |
op_relation |
doi:10.5194/nhess-20-877-2020 https://nhess.copernicus.org/articles/20/877/2020/ |
op_doi |
https://doi.org/10.5194/nhess-20-877-2020 |
container_title |
Natural Hazards and Earth System Sciences |
container_volume |
20 |
container_issue |
3 |
container_start_page |
877 |
op_container_end_page |
888 |
_version_ |
1766134690084814848 |