The Impact of Thunderstorms on Take-off Data in South Africa

<p>Aviation and meteorology are entwined disciplines, as aviation occurs in the atmosphere. Prevailing weather conditions at take-off are of utmost importance to aviation. This determines the payload of the aircraft and runway in use. Forecast verification is essential to aviation as it determines the quality of the forecasting products. The tolerances for take-off data are stringent and slightly relaxed tolerances are used in South Africa by mutual agreement.</p> <p>There are six aerodromes in South Africa where Take-off Data are produced, in varying climatic conditions as South Africa is in both the tropics and midlatitudes. Thunderstorms are a common occurrence over the central and eastern interior, but less so in the southwest of the country. For this study, operational observational data, as well as Take-off Data forecasts were divided into two datasets one with days of thunderstorms and one with days without thunderstorms. The in-house verification tool was run on both datasets individually to determine the accuracy of the operational forecasts.</p> <p>The data period for consideration was January 2019 – March 2022, resulting in three years of data being processed. The data was further divided into the Corporate Quarters of the South African Weather Service, to gain insight into seasonal change. Only the first three hours of Take-Off Data forecasts are evaluated to ensure consistency as the length of Take-off Data varies from office to office.</p> <p>The results indicated that for most instances, the days without thunderstorms fared better than the days with thunderstorms. Temperatures were the rare exception for King Shaka International and Chief David Stuurman International (Port Elizabeth) Airports. It was found that the interior stations averaged a drop of 2.5%, which if considered the high levels of accuracy required can have significant impact on the results.</p>