Storm surge is the abnormal rise in sea level generated by a hurricane or other intense storm, over and above the predicted or normal astronomical tide.

It is caused mainly by atmospheric weather systems such as tropical cyclones, hurricane winds shoving the ocean water up over the coast, although low pressure in the eye also contributes a much smaller amount. The height of water level rise due to storm surge is the difference at the coast between the observed level of the sea surface and the level that would have occurred in the absence of the tropical cyclone.