Jumpiness in ensemble forecasts of Atlantic tropical cyclone tracks
We investigate the run-to-run consistency (jumpiness) of ensemble forecasts of tropical cyclone tracks from three global centers: ECMWF, the Met Office and NCEP. We use a divergence function to quantify the change in cross-track position between consecutive ensemble forecasts initialized at 12-hour...
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American Meteorological Society
2024
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ftunivreading:oai:centaur.reading.ac.uk:114359 2024-04-28T08:30:58+00:00 Jumpiness in ensemble forecasts of Atlantic tropical cyclone tracks Richardson, David S. Cloke, Hannah L. Methven, John A. Pappenberger, Florian 2024-01 text https://centaur.reading.ac.uk/114359/ https://centaur.reading.ac.uk/114359/3/114359%20VoR.pdf https://centaur.reading.ac.uk/114359/1/DRichardson_TC_jumpiness_WAF_revision_clean.docx en eng American Meteorological Society https://centaur.reading.ac.uk/114359/3/114359%20VoR.pdf https://centaur.reading.ac.uk/114359/1/DRichardson_TC_jumpiness_WAF_revision_clean.docx Richardson, D. S., Cloke, H. L. <https://centaur.reading.ac.uk/view/creators/90004850.html> orcid:0000-0002-1472-868X , Methven, J. A. <https://centaur.reading.ac.uk/view/creators/90000334.html> orcid:0000-0002-7636-6872 and Pappenberger, F. (2024) Jumpiness in ensemble forecasts of Atlantic tropical cyclone tracks. Weather and Forecasting, 39 (1). pp. 203-215. ISSN 1520-0434 doi: https://doi.org/10.1175/WAF-D-23-0113.1 <https://doi.org/10.1175/WAF-D-23-0113.1> cc_by_4 Article PeerReviewed 2024 ftunivreading https://doi.org/10.1175/WAF-D-23-0113.1 2024-04-03T17:06:02Z We investigate the run-to-run consistency (jumpiness) of ensemble forecasts of tropical cyclone tracks from three global centers: ECMWF, the Met Office and NCEP. We use a divergence function to quantify the change in cross-track position between consecutive ensemble forecasts initialized at 12-hour intervals. Results for the 2019-2021 North Atlantic hurricane season show that the jumpiness varied substantially between cases and centers, with no common cause across the different ensemble systems. Recent upgrades to the Met Office and NCEP ensembles reduced their overall jumpiness to match that of the ECMWF ensemble. The average divergence over the set of cases provides an objective measure of the expected change in cross-track position from one forecast to the next. For example, a user should expect on average that the ensemble mean position will change by around 80-90 km in the cross-track direction between a forecast for 120 hours ahead and the updated forecast made 12 hours later for the same valid time. This quantitative information can support users’ decision making, for example in deciding whether to act now or wait for the next forecast. We did not find any link between jumpiness and skill, indicating that users should not rely on the consistency between successive forecasts as a measure of confidence. Instead, we suggest that users should use ensemble spread and probabilistic information to assess forecast uncertainty, and consider multi-model combinations to reduce the effects of jumpiness. Article in Journal/Newspaper North Atlantic CentAUR: Central Archive at the University of Reading Weather and Forecasting 39 1 203 215 |
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Open Polar |
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CentAUR: Central Archive at the University of Reading |
op_collection_id |
ftunivreading |
language |
English |
description |
We investigate the run-to-run consistency (jumpiness) of ensemble forecasts of tropical cyclone tracks from three global centers: ECMWF, the Met Office and NCEP. We use a divergence function to quantify the change in cross-track position between consecutive ensemble forecasts initialized at 12-hour intervals. Results for the 2019-2021 North Atlantic hurricane season show that the jumpiness varied substantially between cases and centers, with no common cause across the different ensemble systems. Recent upgrades to the Met Office and NCEP ensembles reduced their overall jumpiness to match that of the ECMWF ensemble. The average divergence over the set of cases provides an objective measure of the expected change in cross-track position from one forecast to the next. For example, a user should expect on average that the ensemble mean position will change by around 80-90 km in the cross-track direction between a forecast for 120 hours ahead and the updated forecast made 12 hours later for the same valid time. This quantitative information can support users’ decision making, for example in deciding whether to act now or wait for the next forecast. We did not find any link between jumpiness and skill, indicating that users should not rely on the consistency between successive forecasts as a measure of confidence. Instead, we suggest that users should use ensemble spread and probabilistic information to assess forecast uncertainty, and consider multi-model combinations to reduce the effects of jumpiness. |
format |
Article in Journal/Newspaper |
author |
Richardson, David S. Cloke, Hannah L. Methven, John A. Pappenberger, Florian |
spellingShingle |
Richardson, David S. Cloke, Hannah L. Methven, John A. Pappenberger, Florian Jumpiness in ensemble forecasts of Atlantic tropical cyclone tracks |
author_facet |
Richardson, David S. Cloke, Hannah L. Methven, John A. Pappenberger, Florian |
author_sort |
Richardson, David S. |
title |
Jumpiness in ensemble forecasts of Atlantic tropical cyclone tracks |
title_short |
Jumpiness in ensemble forecasts of Atlantic tropical cyclone tracks |
title_full |
Jumpiness in ensemble forecasts of Atlantic tropical cyclone tracks |
title_fullStr |
Jumpiness in ensemble forecasts of Atlantic tropical cyclone tracks |
title_full_unstemmed |
Jumpiness in ensemble forecasts of Atlantic tropical cyclone tracks |
title_sort |
jumpiness in ensemble forecasts of atlantic tropical cyclone tracks |
publisher |
American Meteorological Society |
publishDate |
2024 |
url |
https://centaur.reading.ac.uk/114359/ https://centaur.reading.ac.uk/114359/3/114359%20VoR.pdf https://centaur.reading.ac.uk/114359/1/DRichardson_TC_jumpiness_WAF_revision_clean.docx |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
https://centaur.reading.ac.uk/114359/3/114359%20VoR.pdf https://centaur.reading.ac.uk/114359/1/DRichardson_TC_jumpiness_WAF_revision_clean.docx Richardson, D. S., Cloke, H. L. <https://centaur.reading.ac.uk/view/creators/90004850.html> orcid:0000-0002-1472-868X , Methven, J. A. <https://centaur.reading.ac.uk/view/creators/90000334.html> orcid:0000-0002-7636-6872 and Pappenberger, F. (2024) Jumpiness in ensemble forecasts of Atlantic tropical cyclone tracks. Weather and Forecasting, 39 (1). pp. 203-215. ISSN 1520-0434 doi: https://doi.org/10.1175/WAF-D-23-0113.1 <https://doi.org/10.1175/WAF-D-23-0113.1> |
op_rights |
cc_by_4 |
op_doi |
https://doi.org/10.1175/WAF-D-23-0113.1 |
container_title |
Weather and Forecasting |
container_volume |
39 |
container_issue |
1 |
container_start_page |
203 |
op_container_end_page |
215 |
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1797588662651715584 |