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Flash Flood
This hard-to-detect, sudden, and dangerous event should be on your top priority on 'Danger' lists if you live near large bodies of water.

What is a flood?
Floods happen when an excess of water flows out from a large body of water. This can be caused by falied dams, too much rain, and glacial melting. There are four types of floods. Areal floods happen when there is too much rain and too little places for the rain to all go. Riverine floods are caused when rivers exceed their normal volume and water breaks the leevee of the river. This can be caused by storms and, in Asian countries, monsoons. Urban flooding happens when storm sewers fail to take in water in cities quickly enough, and/or when lots of snow melts simultaneously. Coastal flooding can occur when a large storm hits. This storm may force excesses of water onto harbors, therefore causing waves which may overflow into urban areas. Catastrophic floods happen when human made objects are destroyed, such as dams and dikes, which causes a large outflow of water which may flood entire towns.

Variables that can affect flood development ; flood prediction
Floods can be affected by amount of rain; this is usually the case for areal floods. Strength of storms often allow one to determine whether there is a flood or not. Usually it is extremely hard to detect flash floods; the suddenness of a dam exploding or an tropical storm makes it hard to get ready before it strikes.