What Causes a Storm Surge, and What Are Its Damaging Effects?

Whether or not you’re expected to be in the path of a hurricane, it’s wise to know just what to do should one come your way. That includes being informed on everything to expect, such as the dangers you and your property could be facing.

Storm surges are a particularly threatening aspect of hurricanes. In fact, the National Hurricane Center claims they are “often the greatest threat to life and property from a hurricane.” Here’s everything you need to know, including what causes a storm surge, what types of damage they can cause, and how to prepare.

Hurricane Florence
Hurricane Florence | NASA via Getty Images

What is a storm surge?

The National Hurricane Center describes a storm surge as “an abnormal rise of water generated by a storm, over and above the predicted astronomical tide.” And when a storm surge and an astronomical tide combine, it creates a storm tide (risen water levels during a storm).

While locations along the coast are vulnerable to storm surges, the water’s edge isn’t all that’s in danger. During 2008’s Hurricane Ike, a Category 4 storm, the storm surge traveled 30 miles inland in Texas and Louisiana.

What causes a storm surge?

Storm surges occur when winds from a hurricane blow onshore. As the wind circulates around the eye of the storm, it blows on the ocean surface and creates a vertical circulation.

“Once the hurricane reaches shallower waters near the coast, the vertical circulation in the ocean becomes disrupted by the ocean bottom,” according to the National Hurricane Center. “The water can no longer go down, so it has nowhere else to go but up and inland.”

Hurricane Ivan
Hurricane Ivan | Stacey Pardini/U.S. Coast Guard via Getty Images

What is the best way to prepare for a storm surge?

According to Joel Cline, a tropical program coordinator with the National Weather Service, all you can do to prepare for a storm surge is evacuate. “You really can’t run away from the winds of a hurricane, but you can avoid the water,” he explained.

While getting your family and pets to a safe place should be your first priority, Cline also advises gathering the essentials. Items on your list should include fresh water, canned food, a handheld can opener, batteries, battery-operated radios, propane, and flashlights. He also recommends bringing along important documents in waterproof bags.

Most importantly, listen to and obey evacuation orders. If your area is deemed too dangerous to stay in, don’t take any risks. You may also be advised to shut off gas and electricity in your home. Therefore, it’s important to educate yourself on how to do so beforehand.

What are the damaging effects of a storm surge?  

A storm surge can do major damage to anything (or anyone) in its path. The extreme rise in water levels and strong winds can cause severe flooding, property damage, and beach and coastal highway erosion.

The life-threatening nature of storm surges is nothing to take a chance on. According to Cline, “Storm surges in general used to be a leading cause of fatality with hurricanes, but now — because of evacuations and getting the word out so far in advance — [the number of deaths] has gone down. But [storm surges] still remain to be the potential largest loss of life from a hurricane.”