Assessment of subseasonal-to-seasonal (S2S) ensemble extreme precipitation forecast skill over Europe
<p>Heavy precipitation can lead to floods and landslides, resulting in widespread damage and significant casualties. Some of its impacts can be mitigated if reliable forecasts and warnings are available. Of particular interest is the subseasonal-to-seasonal (S2S) prediction timescale. The S2S...
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2023-08-01
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| Series: | Natural Hazards and Earth System Sciences |
| Online Access: | https://nhess.copernicus.org/articles/23/2857/2023/nhess-23-2857-2023.pdf |
| _version_ | 1797737199583625216 |
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| author | P. Rivoire P. Rivoire P. Rivoire O. Martius O. Martius O. Martius P. Naveau A. Tuel A. Tuel |
| author_facet | P. Rivoire P. Rivoire P. Rivoire O. Martius O. Martius O. Martius P. Naveau A. Tuel A. Tuel |
| author_sort | P. Rivoire |
| collection | DOAJ |
| description | <p>Heavy precipitation can lead to floods and landslides, resulting in widespread damage and significant casualties. Some of its impacts can be mitigated if reliable forecasts and warnings are available. Of particular interest is the subseasonal-to-seasonal (S2S) prediction timescale. The S2S prediction timescale has received increasing attention in the research community because of its importance for many sectors. However, very few forecast skill assessments of precipitation extremes in S2S forecast data have been conducted. The goal of this article is to assess the forecast skill of rare events, here extreme precipitation, in S2S forecasts, using a metric specifically designed for extremes. We verify extreme precipitation events over Europe in the S2S forecast model from the European Centre for Medium-Range Weather Forecasts. The verification is conducted against ERA5 reanalysis precipitation. Extreme precipitation is defined as daily precipitation accumulations exceeding the seasonal 95th percentile. In addition to the classical Brier score, we use a binary loss index to assess skill. The binary loss index is tailored to assess the skill of rare events. We analyze daily events that are locally and spatially aggregated, as well as 7 d extreme-event counts. Results consistently show a higher skill in winter compared to summer. The regions showing the highest skill are Norway, Portugal and the south of the Alps. Skill increases when aggregating the extremes spatially or temporally. The verification methodology can be adapted and applied to other variables, e.g., temperature extremes or river discharge.</p> |
| first_indexed | 2024-03-12T13:23:59Z |
| format | Article |
| id | doaj.art-1ec0b9a3c86e463db874e7fbee25e67e |
| institution | Directory Open Access Journal |
| issn | 1561-8633 1684-9981 |
| language | English |
| last_indexed | 2024-03-12T13:23:59Z |
| publishDate | 2023-08-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Natural Hazards and Earth System Sciences |
| spelling | doaj.art-1ec0b9a3c86e463db874e7fbee25e67e2023-08-25T08:34:11ZengCopernicus PublicationsNatural Hazards and Earth System Sciences1561-86331684-99812023-08-01232857287110.5194/nhess-23-2857-2023Assessment of subseasonal-to-seasonal (S2S) ensemble extreme precipitation forecast skill over EuropeP. Rivoire0P. Rivoire1P. Rivoire2O. Martius3O. Martius4O. Martius5P. Naveau6A. Tuel7A. Tuel8Institute of Geography, University of Bern, Bern, SwitzerlandOeschger Centre for Climate Change Research, University of Bern, Bern, SwitzerlandInstitute of Earth Surface Dynamics, Faculty of Geosciences and Environment, University of Lausanne, Lausanne, SwitzerlandInstitute of Geography, University of Bern, Bern, SwitzerlandOeschger Centre for Climate Change Research, University of Bern, Bern, SwitzerlandMobiliar Lab for Natural Risks, University of Bern, Bern, SwitzerlandLaboratoire des Sciences du Climat et de l'Environnement, ESTIMR, CNRS-CEA-UVSQ, Gif-sur-Yvette, FranceInstitute of Geography, University of Bern, Bern, SwitzerlandOeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland<p>Heavy precipitation can lead to floods and landslides, resulting in widespread damage and significant casualties. Some of its impacts can be mitigated if reliable forecasts and warnings are available. Of particular interest is the subseasonal-to-seasonal (S2S) prediction timescale. The S2S prediction timescale has received increasing attention in the research community because of its importance for many sectors. However, very few forecast skill assessments of precipitation extremes in S2S forecast data have been conducted. The goal of this article is to assess the forecast skill of rare events, here extreme precipitation, in S2S forecasts, using a metric specifically designed for extremes. We verify extreme precipitation events over Europe in the S2S forecast model from the European Centre for Medium-Range Weather Forecasts. The verification is conducted against ERA5 reanalysis precipitation. Extreme precipitation is defined as daily precipitation accumulations exceeding the seasonal 95th percentile. In addition to the classical Brier score, we use a binary loss index to assess skill. The binary loss index is tailored to assess the skill of rare events. We analyze daily events that are locally and spatially aggregated, as well as 7 d extreme-event counts. Results consistently show a higher skill in winter compared to summer. The regions showing the highest skill are Norway, Portugal and the south of the Alps. Skill increases when aggregating the extremes spatially or temporally. The verification methodology can be adapted and applied to other variables, e.g., temperature extremes or river discharge.</p>https://nhess.copernicus.org/articles/23/2857/2023/nhess-23-2857-2023.pdf |
| spellingShingle | P. Rivoire P. Rivoire P. Rivoire O. Martius O. Martius O. Martius P. Naveau A. Tuel A. Tuel Assessment of subseasonal-to-seasonal (S2S) ensemble extreme precipitation forecast skill over Europe Natural Hazards and Earth System Sciences |
| title | Assessment of subseasonal-to-seasonal (S2S) ensemble extreme precipitation forecast skill over Europe |
| title_full | Assessment of subseasonal-to-seasonal (S2S) ensemble extreme precipitation forecast skill over Europe |
| title_fullStr | Assessment of subseasonal-to-seasonal (S2S) ensemble extreme precipitation forecast skill over Europe |
| title_full_unstemmed | Assessment of subseasonal-to-seasonal (S2S) ensemble extreme precipitation forecast skill over Europe |
| title_short | Assessment of subseasonal-to-seasonal (S2S) ensemble extreme precipitation forecast skill over Europe |
| title_sort | assessment of subseasonal to seasonal s2s ensemble extreme precipitation forecast skill over europe |
| url | https://nhess.copernicus.org/articles/23/2857/2023/nhess-23-2857-2023.pdf |
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