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What is storm surge, why is it so dangerous

Several factors influence maximum potential storm surge

A man walks through storm surge on the flooded road into Horseshoe Beach, Fla., Monday morning, Aug. 5, 2024. Hurricane Debby made landfall early this morning. (AP Photo/Christopher O'Meara) (Chris O'Meara, Copyright 2024 The Associated Press. All rights reserved.)

ORLANDO, Fla. – Communities along the U.S. east and Gulf coasts are particularly vulnerable when it comes to storm surge.

Storm surge is water pushed toward the shore by the force of the strong winds moving around a tropical storm or hurricane.

The wind circulation around the storm’s eye creates a vertical circulation in the deep ocean. Once the storm nears the coast as a tropical storm or hurricane, the vertical circulation of the ocean gets disrupted by the ocean bottom and since the water can no longer go up and down, it goes inland.

According to the National Weather Service, there are multiple factors that influence the maximum potential storm surge for a certain location.

  • Central pressure: Lower pressure will produce a higher surge.
  • Storm intensity: Stronger winds will produce a higher surge.
  • Size of the storm: A larger storm will produce higher surge.
  • Storm forward speed: A faster storm will produce a higher surge, but a higher surge is seen in bays, sounds and other enclosed bodies of water with a slower storm.
  • Angle of approach to the coast: A storm moving perpendicular to the coast is more likely to produce higher storm surge than a storm moving parallel to the coast.
  • Shape of the coastline: Storm surge will be higher when a storm makes landfall somewhere on a coastline that’s curved inward rather than curved outward.
  • Width, slope of the ocean bottom: Higher storm surge happens with a wide, gently sloping shelf and lower storm surge happened with a narrow, steep shelf.
  • Local features: Storm surge is also dependent on local features and barriers that could affect the flow of water.

Storm surge combined with normal waves can destroy buildings and threaten lives.

“Water weighs approximately 1,700 pounds per cubic yard; extended pounding by frequent waves can demolish any structure not specifically designed to withstand such forces. The two elements work together to increase the impact on land because the surge makes it possible for waves to extend inland.”

How to protect your home from storm surge

There are several ways you can protect your home from storm surge if you live along the coast.

FEMA suggests the following steps to help minimize any damage to your property:

Outside your home

[RELATED: Have ‘zombie trees?’ Here’s what to look for during hurricane season prep around your house]

Inside your home

  • Prepare or update list of belongings (this can help with the insurance process if you need to file a claim)
  • Store valuables
  • Elevate appliances and utilities on higher floors

Long-term planning to prepare your property could also include elevating your home.

Tony Hake with FEMA’s Federal Insurance Division said there is difference between homeowners and flood insurance and people should buy flood insurance early.

“There is a waiting period, a 30-day waiting period for your policy to go into effect. So to purchase early, you know, if you see a storm coming your way and it’s a week out, it’s not going to cover it because you have a 30-day waiting period. But. I would encourage people to talk to their insurance agents,” he said.

Evacuate if necessary

If authorities are advising you to evacuate your home, do so immediately. If floodwater is present on roads, bridges or the ground, don’t cross it. Avoid moving water as it has tremendous power.

If you’re trapped, call 911 and give your location to first responders. If you’re in a building, go to the highest level. Only go onto your roof if necessary and signal for help. If your vehicle is trapped in fast-moving water, stay in the car. If water is rising in the car, get on the roof. If you’re outside, move to higher ground.

Only return to your home when authorities say it is safe.


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