Woodhams, BJ orcid.org/0000-0003-2070-8279, Birch, CE, Marsham, JH orcid.org/0000-0003-3219-8472 et al. (3 more authors) (2018) What is the added-value of a convection-permitting model for forecasting extreme rainfall over tropical East Africa? Monthly Weather Review, 146 (9). pp. 2757-2780. ISSN 0027-0644
Abstract
Forecasting convective rainfall in the tropics is a major challenge for numerical weather prediction. The use of convection-permitting (CP) forecast models in the tropics has lagged behind the mid-latitudes, despite the great potential of such models in this region. In the scientific literature, there is very little evaluation of CP models in the tropics, especially over an extended time period. This paper evaluates the prediction of convective storms for a period of two years in the Met Office operational CP model over East Africa and the global operational forecast model. A novel localised form of the Fractions Skill Score is introduced, which shows variation in model skill across the spatial domain. Overall, the CP model and the global model both outperform a 24-hour persistence forecast. The CP model shows greater skill than the global model, in particular on sub-daily timescales and for storms over land. Forecasts over Lake Victoria are also improved in the CP model, with an increase in hit rate of up to 20%. Contrary to studies in the mid-latitudes, the skill of both models shows a large dependence on the time of day and comparatively little dependence on the forecast lead time within a 48-hour forecast. Although these results provide more motivation for forecasters to use the CP model to produce sub-daily forecasts with increased detail, there is a clear need for more in-situ observations for data assimilation into the models and for verification. A move towards ensemble forecasting could have further benefits.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2018 American Meteorological Society. This article is licensed under a Creative Commons Attribution 4.0 license (http://creativecommons.org/licenses/by/4.0/). |
Keywords: | Africa; Inland seas/lakes; Rainfall; Cloud resolving models; Model evaluation/performance; Regional models |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Inst for Climate & Atmos Science (ICAS) (Leeds) |
Funding Information: | Funder Grant number NERC NE/M02038X/1 NERC NE/P021077/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 09 Jul 2018 10:42 |
Last Modified: | 28 Aug 2018 00:35 |
Status: | Published |
Publisher: | American Meteorological Society |
Identification Number: | 10.1175/MWR-D-17-0396.1 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:132945 |