Flash floods are distinguished from a regular flood by the length of time it takes for the flood to occur. Under six hours, the flood is referred to as a flash flood. Some can occur within minutes. Areas will not always be able receive a warning that these floods are coming and people can be caught off-guard.
Each year, more deaths occur due to flooding than from any other severe weather related hazard. People underestimate the force and power of water. More than half of all flood related deaths in the US result from vehicles being swept downstream.
Floods are most often caused by intense rainfall over a short period of time, prolonged heavy rain, a dam or levee failure, or a sudden release of water held by an ice or debris jam. Most flooding conditions are associated with seasonal weather. Floods can be caused by melting snow combined with rain in the winter and early spring, severe thunderstorms in the spring and summer, and hurricanes in the summer and fall. However, any source of water can potentially cause a flood.