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Characteristics of warm season supercell thunderstorms over the Gauteng and Mpumalanga Provinces of South Africa

Dissertation (MSc (Meteorology))--University of Pretoria, 2021.

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Other Authors: Dyson, Liesl L.
Format: Thesis
Language:English
Published: University of Pretoria 2022
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access_status_str Open Access
author2 Dyson, Liesl L.
author_browse Dyson, Liesl L.
author_facet Dyson, Liesl L.
collection Thesis
dc_rights_str_mv © 2022 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria.
description Dissertation (MSc (Meteorology))--University of Pretoria, 2021.
format Thesis
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institution University of Pretoria (South Africa)
language English
last_indexed 2026-06-10T12:36:52.135Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository
publishDate 2022
publishDateRange 2022
publishDateSort 2022
publisher University of Pretoria
publisherStr University of Pretoria
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spelling oai:repository.up.ac.za:2263/83956 Characteristics of warm season supercell thunderstorms over the Gauteng and Mpumalanga Provinces of South Africa Dyson, Liesl L. cgthaele@gmail.com Becker, Erik H. Liesker, Christina Gabriele UCTD Meteorology Climatology Remote sensing Natural and agricultural sciences theses SDG-13 SDG-13: Climate action Dissertation (MSc (Meteorology))--University of Pretoria, 2021. A supercell thunderstorm, notorious for producing large hail, damaging winds, tornadoes, and flooding, often results in damage to property, injuries, and loss of life. Supercells were previously considered rare in South Africa, but in more recent years, evidence has shown this not to be the case. With the installation of the South African Weather Service Doppler radar network in 2010, several cases have since been detected. However, no radar-derived database exists and research on supercells, including their occurrence and characteristics, is limited over South Africa. The aim of this research is to investigate the characteristics of supercells over the Gauteng and Mpumalanga provinces of South Africa during the warm seasons (September to February) of 2010 to 2020. To achieve this a radar-derived database was created, using all available radar data from the Irene and Ermelo radar, with as many supercells identified as possible. These supercells were analysed to investigate their temporal, spatial, track and lifespan characteristics. A database comprising 115 left-moving and 6 right-moving events over 67 event days was established. On a given event day an average of 2 supercells were found to occur with their activity peaking in the afternoon between 13:00 and 14:00 UTC. On average 13 supercell events and 7 event days (containing at least 1 supercell) occurred per season and their frequency peaked between October and November. The peak in the monthly distribution occurred earlier over Gauteng in October and November, but over Mpumalanga the peak was later during December. Supercell activity occurred over the southern Highveld in September, spreading northwards by October and then to the south-east, while decreasing in the west, in December. The spatial distribution (initiation, track, and demise) showed hotspots in activity in places over southern Gauteng as well as the south-eastern parts of Mpumalanga. Supercells were predominantly short-lived (lasting ≤ 2 hours), with only 12 moderate-lived left-moving events (lasting > 2 hours but < 4 hours). On average the left-moving events lasted 1 hour 12 minutes, tracking an average distance of 49 km, while on average right-moving events lasted 49 minutes and tracked 27 km. The left-moving supercells had an average track from the south-west to north-east, however, their track shifted from west south-westerly earlier in the season to southerly in January. All right-moving supercell events had a track from the north-west to south-east. The short-term radar-based climatology of supercell characteristics that were identified in this research, will allow for a better understanding and thus potentially improving forecasting, nowcasting and warning for these thunderstorms over the Gauteng and Mpumalanga provinces of South Africa. A further investigation into the environment and topography over the area is required, to fully understand why these characteristics were observed. The radar-derived supercell database is a first for South Africa and thus provides a foundation on which numerous other studies can be conducted. Geography, Geoinformatics and Meteorology MSc (Meteorology) Unrestricted 2022-02-16T07:41:18Z 2022-02-16T07:41:18Z 2022-04-28 2021 Dissertation Liesker, CG 2021, Characteristics of warm season supercell thunderstorms over the Gauteng and Mpumalanga Provinces of South Africa, MSc Dissertation, University of Pretoria, viewed yymmdd http://hdl.handle.net/2263/83956 A2022 http://hdl.handle.net/2263/83956 DOI: https://doi.org/10.25403/UPresearchdata.23617092.v2 en © 2022 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria
spellingShingle UCTD
Meteorology
Climatology
Remote sensing
Natural and agricultural sciences theses SDG-13
SDG-13: Climate action
Characteristics of warm season supercell thunderstorms over the Gauteng and Mpumalanga Provinces of South Africa
title Characteristics of warm season supercell thunderstorms over the Gauteng and Mpumalanga Provinces of South Africa
title_full Characteristics of warm season supercell thunderstorms over the Gauteng and Mpumalanga Provinces of South Africa
title_fullStr Characteristics of warm season supercell thunderstorms over the Gauteng and Mpumalanga Provinces of South Africa
title_full_unstemmed Characteristics of warm season supercell thunderstorms over the Gauteng and Mpumalanga Provinces of South Africa
title_short Characteristics of warm season supercell thunderstorms over the Gauteng and Mpumalanga Provinces of South Africa
title_sort characteristics of warm season supercell thunderstorms over the gauteng and mpumalanga provinces of south africa
topic UCTD
Meteorology
Climatology
Remote sensing
Natural and agricultural sciences theses SDG-13
SDG-13: Climate action
url http://hdl.handle.net/2263/83956