Irma damage expected to reach $18 billion in the U.S.

Insured losses from Hurricane Irma could total $18 billion in the U.S., far less than anticipated when the storm was barreling toward Florida’s east coast as a Category 4 monster but still among the nation’s worst.

Karen Clark and Co., a Boston-based firm that analyzes risk, estimated total losses, including the Caribbean, at $25 billion. Florida accounts for most of the $18 billion in the U.S., followed by Georgia, South Carolina and Alabama. The estimate covers damage to buildings and their contents, other insured structures, and vehicles and the disruption to business. It does not include crop losses or losses covered by the nation’s flood insurance program, Clark said.

The estimate also does not cover the total cost of the storm, which can be a trickier number to calculate, she said.

“It would include infrastructure: damage to roads, beach erosion, cleanup efforts. All these other things that go into total economic loss, which are squishier numbers. I don’t know of any organization that tallies that.”

At that amount, Irma falls just outside the top 10 list and above the $15.4 billion Clark estimated for Harvey’s losses. The 1926 Miami hurricane still ranks as the worst in the U.S., according to Clark’s tally, with losses in today’s dollars totaling $150 billion. That’s followed by the 1928 hurricane that struck Lake Okeechobee at $77 billion, the 1900 hurricane in Galveston at $60 billion and 2005’s Katrina, which generated $59 billion in insured losses, she said.

Irma became the second Category 4 storm to strike the U.S. in less than a month when it made landfall Sunday morning on Cudjoe Key and the first Cat 4 in Florida since 2004’s Charley. Irma will also go down as one of the Atlantic’s strongest hurricanes on record, with peak winds of 185 mph lasting 37 hours.

After South Florida was forecast as a potential target for a Cat 4 Irma, Clark told clients that losses could rise as high as $150 billion.

“That is the worst location for a major storm,” she said. “A strong Cat 4 on that track? Yes, it would be over $150 billion.”

After Irma began to weaken, potential losses dropped significantly. Irma also turned out to be a much dryer storm than the worst case scenarios forecasters warned about, with severe storm surge in Tampa and St. Petersburg never materializing. In wet storms like Katrina and Harvey, flood losses, which are usually not insured, can be much higher.

Irma delivered her worst blow to the Keys, which the storm struck with 130 mph sustained winds. Most of that was limited to mobile homes, roofs and windows, light structures and signs, Clark said. Outside the Keys, damage was mostly caused by falling trees. Once the storm crossed into the Gulf, it weakened considerably as it ran up the coast, although homes in Everglades City were hit hard.

The storm also triggered surprisingly severe coastal flooding farther north in Jacksonville and Charleston, where Irma’s surge coincided with high tide and heavy rain. In Jacksonville, the St. Johns River rose to almost six feet, and rain totals reached 11 inches.

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