|Tropical cyclones threaten lives and property because of their high winds, associated storm surge, excessive rain and flooding, and ability to spawn tornadoes.
As they make landfall, the winds and surge are the main threats. Hurricane-force winds, by definition, exceed 119 kilometers per hour (74 mph) and have been recorded at over 325 kph (200 mph). At the low end of this scale, trees can be uprooted. At the high end, buildings are completely destroyed. As strong winds blow across an ocean surface they create a large dome of water. The resulting storm surge presents a serious coastal hazard as hurricanes make landfall.