A $150 Billion Misfire: How Disaster Models Got Irma Wrong

Twenty miles may have made a $150 billion difference.

Estimates for the damage Hurricane Irma would inflict on Florida kept mounting as it made its devastating sweep across the Caribbean. It was poised to be the costliest U.S. storm on record. Then something called the Bermuda High intervened and tripped it up.

“We got very lucky,” said Jeff Masters, co-founder of Weather Underground in Ann Arbor, Michigan. If Irma had passed 20 miles west of Marco Island instead of striking it on Sunday, “the damage would have been astronomical.” A track like that would have placed the powerful, eastern eye wall of Irma on Florida’s Gulf Coast.

By one estimate, the total cost dropped to about $50 billion Monday from $200 billion over the weekend. The state escaped the worst because Irma’s eye shifted away from the biggest population center of Miami-Dade County.

The credit goes to the Bermuda High, which acts like a sort of traffic cop for the tropical North Atlantic Ocean. The circular system hovering over Bermuda jostled Irma onto northern Cuba Saturday, where being over land sapped it of some power, and then around the tip of the Florida peninsula, cutting down on storm surge damage on both coasts of the state.

“The Bermuda High is finite and it has an edge, which was right over Key West,” Masters said. Irma caught the edge and turned north.

    Originally published at: http://www.bloomberg.com/