Many earthquakes occur where the earth's crustal plates grind and shift along one another. Flash floods can be caused by situations such as a sudden excessive rainfall, the failure of a dam, or the thaw of an ice jam. During recent years, floods and flash floods have caused billions of dollars in damage each year. They are among the most common and widespread of all natural hazards. Even more importantly, they're the number one weather-related killer.
Flooding is caused in a variety of ways.
Winter or spring rains, coupled with melting snows, can fill river basins too quickly. Torrential rains from decaying hurricanes or other tropical systems can also produce river flooding. The Mississippi River Flood of 1993 was caused by repeated heavy rain from thunderstorms over a period of weeks. This same tropical cyclone is known as a typhoon in the western Pacific and a cyclone in the Indian Ocean. A formal advisory issued by forecasters at the National Hurricane Center when they have determined that hurricane conditions are expected in a coastal area or group of islands within a 24-hour period.