Flooding

Many floods are directly related to changes in weather. The most common cause of flooding is due to rain falling at extremely high rates or for an unusually long period of time. Additionally, areas that experience a great deal of snow in winter are prone to springtime flooding when the snow and ice melt, especially if the thaw is relatively sudden. Furthermore, rainfall and snowmelt can sometimes combine to cause floods.

Sometimes, floods occur as a result of a unique combination of factors that only indirectly involve weather conditions. For instance, a low-lying coastal area may be prone to flooding whenever the ocean is at high tide. Exceptionally high tides may be attributed to a storm caused by a combination of factors, like low barometric pressure and high winds. Finally, floods sometimes can occur regardless of the climate. Examples are tsunamis (seismic waves on the sea or large lakes that are caused by earthquakes), volcanic heating and rapid melting of a snow pack atop a volcanic mountain or under a glacier, or even failures of natural or man-made dams.