Tropical cyclones are powerful and destructive weather systems that form over warm tropical ocean basins. where sea surface temperatures are above 26.5 degree C. These storms are characterised by strong winds, heavy precipitation and storm surges and can cause significant damage to coastal communities and infrastructure.
Climatologically, tropical cyclones form mainly in the North Atlantic, East Pacific, West Pacific, South Pacific and the Indian Ocean. Out of 85 tropical storms that develop annually over the warm tropical oceans, more than half (45) of them intensify into tropical cyclones. The Western Pacific basin is the most active region for tropical cyclones and accounts for about a third of the world’s tropical cyclones. The North Indian basin accounts for only about 4% of the global total, although it is one of the most vulnerable regions in the world to the effects of such cyclones.
The Saffir-Simpson (SS) hurricane wind scale, introduced in the early 1970s, is the most widely used metric for warning the public about the dangers of tropical cyclones. The SS hurricane wind scales are categorised by the maximum sustained wind speed at a height of 10 metres. Although most tropical cyclone-related deaths are caused by storm surge and heavy rainfall, wind hazard remains an important metric for communicating risk to the public and a critical metric for measuring the impact of these cyclones. There are five categories on the SS hurricane wind scale — category 1 to category 5 — with category 5 wind speed exceeding 252 km/hour. The combined effects of wind, storm surge, and rainfall in a category 5 impact would completely raze any structure.
