Hurricane Isaac reminds that storm surge is biggest threat
Your hurricane experience could be all wrong. If you’ve been through a Category 3 storm and figure a Category 1 will be three times less powerful and, therefore, three times less eventful, you could be in for an unfortunate surprise. Some residents of coastal Louisiana may have underestimated Hurricane Isaac, especially if they were measuring the storm against Hurricane Katrina.
“We’ve never seen anything like this, not even Katrina,” said a visibly rattled parish president in a New York Times article on the flooding outside New Orleans’ levees. In a related news article, Hurricane Isaac survivors said they were surprised by the flooding. Why are people always surprised? The weather is full of surprises. And yet, too many people continue to gauge the strength of a hurricane by the power of the wind alone and ignore the power of the accompanying storm surge. Big mistake.
The Saffir-Simpson Hurricane Wind Scale gives only part of the story. If you live anywhere near the coast, you must learn about the risk of storm surge. Earlier versions of the wind scale incorporated storm surge, but scientists now say there are so many variables in storm surge predictions that providing “average storm surge values” is, well, valueless. Storm surge forecasts use a computer model called SLOSH, which stands for Sea, Lake and Overland Surges from Hurricanes. You should know what the SLOSH model shows for your particular area.
The National Weather Service had considered developing a storm surge scale with the wind scale, but rejected the idea. The explanation says the storm surge scale doesn’t take into account local differences in the shallowness or depth of ocean water, so predicting an “average” storm surge is ineffective.
When a tropical storm threatens, you can find the storm surge predictions for your area at the National Hurricane Center website. In a previous post, I wrote of a report showing a difference between storm surge zones and flood zones. Did you know you could be outside a flood zone and inside a storm surge zone? Now you do. A flood zone is defined as an area at risk from fresh-water flooding. Storm surge is water pushed inland from the ocean by the high winds of a hurricane – and a Category 1 or 2 storm is powerful enough to push tons of water inland.
Storm surge is the greatest threat to life and property from a hurricane. Most homeowner insurance policies do not cover flood damage. Call your insurance company and ask about flood coverage. Also visit www.FloodSmart.gov to learn about flood risks. It’s important protection for when the wind blows and the water rises.