ABSTRACT
Violent weather events, such as hurricanes, tornadoes, major floods and droughts, often result in catastrophic losses of property and income, and on many occasions losses of life. Longer-term weather variations are also important. During the first half of the twentieth century, for example, much of the Northern Hemisphere experienced a period of ‘unusually warm’ weather. Air pollution is also a form of weather modification which affects the ‘value of the atmosphere’. Violent disturbances in the natural atmosphere result in tornadoes, tropical storms, hailstorms, lightning, blizzards, extreme icing conditions and severe dust storms. In economic terms tropical revolving storms are by far the most destructive weather phenomenon. Tornadoes are amongst the most awesome of weather anomalies, the speed of a tornado usually allowing a very limited time for precautions to be taken. Lightning also causes a substantial amount of property damage, either from fires, explosions or falling debris.
