Van Heerden, Johan2022-05-172022-05-1719/10/20211997*https://repository.up.ac.za/handle/2263/85506Dissertation (MSc (Meteorology))--University of Pretoria, 1997.Forecasting short term changes in weather is and will remain a very important but also very difficult task. In order to provide a weather forecaster with the best possible tools to make an accurate weather forecast, it was decided to research the possibility of isentropic analysis methods for South African circumstances. This study introduces the basic concepts of isentropic analysis and the way to interpret variables on isentropic surfaces. Three case studies are presented where significant weather systems influenced the country's weather. In two of the cases heavy rainfall and flooding occurred and in the last case widespread moderate falls were reported. Results of these case studies prove to be very helpful in identifying rainfall areas as well as areas where heavier precipitation could be expected. Operational use of isentropic analysis is recommended.en© 2020 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.UCTDnumerical modelsEta modelisentropic levelsadiabatic conditionssloping surfacethree dimensionaltopographyvertical motiontropical air massheavy rainDissertation