What is a Storm Surge?

Posted by Maureen K. Fleury Jun 6, 2008

In my articles about Hurricane Hazel, Hurricane Katrina and the Galveston Hurricane; I mentioned a storm surge.

If you watch live hurricane broadcasts on networks such as CNN, you will also hear about storm surge.

What is a Storm Surge?

According to the National Hurricane Center: It is water that is pushed toward the shore by the force of the winds swirling around the storm. This advancing surge combines with the normal tides to create the hurricane storm tide. It can increase the water level 15 feet or more. In addition, wind driven waves are superimposed on the storm tide. This rise in water level can cause severe flooding in coastal areas especially when the storm tide coincides with the normal high tides.

Why is a Storm Surge Dangerous?

Because much of the United States Atlantic and Gulf coastlines lie less than 10 feet above mean sea level, the danger from storm tides is tremendous.

Why are Some Storm Surges Worse than Others?

The level of surge in a particular area is also determined by the slope of the continental shelf. A shallow slope off the coast will allow a greater surge to inundate coastal communities. A steeper continental shelf will not see as much surge but large breaking waves can still present major problems. Storm tides, waves, and currents in confined harbors can severely damage ships, marinas, and pleasure boats.

Some people think it’s only the wind from hurricanes that does the damage, but the storm surge is just as bad or worse.