A storm surge is an abnormal rise of water generated by a storm. Strong winds in a tropical cyclone or a sever mid-latitude storm are their primary cause. However, ocean bottom topography, tides, waves and freshwater input from rivers affect the water level rise during a storm surge. The depth of a storm surge can rise quickly — from centimetres to a meter or more in a matter of minutes. It can push an incredible distance beyond the coast. During Hurricane Ike, the surge moved nearly 50 kilometres (30 miles) inland in some locations. A storm surge can travel through bays and up rivers — basically any body of water on or near shore.
The main meteorological factor contributing to a storm surge is high-speed wind pushing water towards the coast over a long fetch. Other factors affecting storm surge severity include the shallowness and orientation of the water body in the storm path, the timing of tides, and the atmospheric pressure drop due to the storm.
Most casualties during tropical cyclones occur as the result of storm surges and surges are a major source of damage to infrastructure and property during storms.As extreme weather becomes more intense and sea level rises due to climate change, storm surge is expected to cause more risk to coastal populations. Communities and governments can adapt by building hard infrastructure, like surge barriers, soft infrastructure, like coastal dunes or mangroves, improving coastal construction practices and building social strategies such as early warning, education and evacuation plans.