Forecasting intense cut-off lows in South Africa using the 4.4 km unified model

Show simple item record Muofhe, Tshimbiluni Percy Chikoore, Hector Bopape, Mary-Jane Morongwa Nethengwe, Nthaduleni Samuel Ndarana, Thando Rambuwani, Gift Tshifhiwa 2021-03-26T11:08:03Z 2021-03-26T11:08:03Z 2020-11
dc.description.abstract Mid-tropospheric cut-off low (COL) pressure systems are linked to severe weather, heavy rainfall and extreme cold conditions over South Africa. They occur during all the above and often result in floods and snowfalls during the winter months, disrupting economic activities and causing extensive damage to infrastructure. This paper examines the evolution and circulation patterns associated with cases of severe COLs over South Africa. We evaluate the performance of the 4.4 km Unified Model (UM) which is currently used operationally by the South African Weather Service (SAWS) to simulate daily rainfall. Circulation variables and precipitation simulated by the UM were compared against European Centre for Medium-Range Weather Forecast’s (ECMWF’s) ERA Interim re-analyses and GPM precipitation at 24-hour timesteps. We present five recent severe COLs, which occurred between 2016 and 2019, that had high impact and found a higher model skill when simulating heavy precipitation during the initial stages than the dissipating stages of the systems. A key finding was that the UM simulated the precipitation differently during the different stages of development and location of the systems. This is mainly due to inaccurate placing of COL centers. Understanding the performance and limitations of the UM model in simulating COL characteristics can benefit severe weather forecasting and contribute to disaster risk reduction in South Africa. en_ZA
dc.description.department Geography, Geoinformatics and Meteorology en_ZA
dc.description.librarian pm2021 en_ZA
dc.description.sponsorship South Africa’s National Research Foundation and the University of Venda’s Research and Publications Committee. en_ZA
dc.description.uri en_ZA
dc.identifier.citation Muofhe, T.P.; Chikoore, H.; Bopape, M.-J.M.; Nethengwe, N.S.; Ndarana, T.; Rambuwani, G.T. Forecasting Intense Cut-Off Lows in South Africa Using the 4.4 km Unified Model. Climate 2020, 8, 129. en_ZA
dc.identifier.issn 2225-1154 (online)
dc.identifier.other 10.3390/cli8110129
dc.language.iso en en_ZA
dc.publisher MDPI en_ZA
dc.rights © 2020 by the authors. Licensee: MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license. en_ZA
dc.subject Circulation patterns en_ZA
dc.subject Heavy precipitation en_ZA
dc.subject Floods en_ZA
dc.subject Forecast skill en_ZA
dc.subject Unified model en_ZA
dc.subject GPM precipitation en_ZA
dc.subject Cut-off low (COL) en_ZA
dc.subject South Africa (SA) en_ZA
dc.title Forecasting intense cut-off lows in South Africa using the 4.4 km unified model en_ZA
dc.type Article en_ZA

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