Storm surge is a large mound of water that accompanies a tropical cyclone as it comes ashore. The intense winds of the cyclone pile up the ocean into a dome of water that is pushed onshore as the cyclone strikes the coast. The low pressure of the cyclone adds to the height of the mound of water, though this is a secondary effect. When the height of a storm surge is discussed it does not take into account the height of the large waves on top of the mound of water.