Hurricane Irma has taken a turn toward the most catastrophically vulnerable big city in America

The devastatingly powerful Hurricane Irma has shifted west into the warm waters of the Gulf of Mexico, with an expected track through the Tampa Bay area, Florida.

The last time a major hurricane hit Tampa Bay, in 1921, its population was about 50,000. Now, it’s a densely populated coastal metropolis of around 3 million residents, with 700 miles of shoreline that are achingly vulnerable to Irma’s storm surge. Karen Clark & Co., a catastrophe modeling firm, estimated that a Hurricane Katrina-sized storm could inflict $175 billion in damage on Tampa Bay, and the surrounding area.

The storm is now projected to make landfall between Naples and Tampa on Sunday afternoon or evening, local time. Even if the storm doesn’t make landfall as it travels up the coast, the area would be in a highly vulnerable position near Irma’s eastern eyewall.

Screenshot 2017-09-10 08.47.06
(Karen Clark & Co)

Miami may have dozens of unsecured construction cranes, but Tampa is even more vulnerable due to shallow offshore waters and natural geography, with the bay acting as a giant funnel that forces water into the city’s numerous channels and bayous.

“A severe storm with the right track orientation will cause an enormous buildup of water that will become trapped in the bay and inundate large areas of Tampa and St. Petersburg,” a 2015 KCC study said. “50% of the population lies on ground elevations of less than 10 feet.”

Irma, which made landfall in the southern Florida Keys on Sunday morning local time, could produce storm surges of up to 15 feet, according to the National Hurricane Center.

“This is fast moving, destructive water,” the Weather Channel’s Bryan Norcross told the Washington Post. “You cannot drive through it and you cannot stand in it. It will sweep buildings away. Storm surge is the deadliest hazard in a hurricane.”

A slightly less dire 2016 study by CoreLogic estimated that about 450,000 Tampa homes—one-third of the total—are vulnerable to hurricane flooding.

Irma storm is expected to impact nearly all of Florida, which has struggled to bring buildings up to code since 1992’s devastating Hurricane Andrew. A majority of southern Florida homes may not be equipped to handle Irma’s havoc.

In Tampa Bay, the safest building is designed to protect art, not people: The Salvador Dali museum was built to withstand a Category 5 hurricane, with 18-inch thick walls, a cast-in-place concrete slab and beam system, pressurized inch-thick glass panels held in place by steel frames, and interior exhibits that can act as sealed vaults.

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