Formation of a storm surge

When a hurricane is forming over open, warm ocean waters, the
wind pushing the water and the low atmospheric pressure in the eye of
the hurricane cause the level of the sea to rise, whipping the water into
gigantic waves. Because this is happening away from land, the water can
escape and move freely away from the building storm. But as the hurricane
moves towards land and the depth of the water becomes more shallow,
the ever-increasing wall of water does not have a chance to flow
away. Instead it is built up around the eye of the hurricane and forms huge
waves. These mountainous waves pound against the land and anything in
its path—buildings, homes, piers, and people. Storm surges can be more
devastating depending upon the strength of the hurricane’s winds and the
shallowness of the off-shore waters.
Storm tide
A storm surge can also become much more destructive if it occurs
during high tide (an increase in water level due to the Moon’s gravitational
pull on Earth). This is called a storm tide. For example, if a normal
high tide for a particular area is three feet and a storm surge occurs at the
same time with fifteen-foot waves, a storm tide with eighteen-foot waves
is formed. This occurrence makes the storm surge even more devastating.