A stochastic model of severe thunderstorms for transmission line design

The importance of wind loading in the design of transmission line structures has been widely recognised. Due to the inherent variabilities of natural phenomena, the modelling of wind loads is a demanding task. Despite the fact that quite extensive research has been carried out in Australia over last 30 years, the wind loads that are generated by high intensive, localised, small-scale wind storms, such as severe thunderstorms, i.e. downbursts are poorly defined. The intention of the present paper is to propose a stochastic model that could realistically and accurately simulate wind loads that are generated by thunderstorm downbursts for transmission line design. The proposed model is then calibrated using existing meteorological records and compared with the results of other similar studies on severe winds. The major advantage of the proposed model for downburst winds is that the size effect of downbursts has been taken into account.