Areas close to the equator, e.g. places like Singapore, are outside the belt of severe tropical cyclone. The monsoon winds over these regions are also mild. Thus, strong winds due to these weather systems are relatively less severe. On the other hand, equatorial regions have frequent tropical thunderstorms. Wind speeds of the gust fronts of these thunderstorms can be relatively high. As the wind characteristics for the thunderstorm (TS) wind and the non-thunderstorm (NTS) wind are expected to be different, it is important to understand their contributions and effects towards the wind loading design of structures. This paper looks at the extreme wind characteristics in Singapore. Extreme wind speeds during thunderstorms and non-thunderstorms are studied. The findings show that while extreme TS gust speeds are consistently higher than those of NTS. Extreme mean wind speeds for TS are smaller than those of NTS. It is also observed that gust factors for peak over IO-min mean as well as peak over hourly mean during thunderstorms are both higher than those for non-thunderstorms. (C) 1999 Elsevier Science Ltd. All rights reserved.
