As it traversed the state of Florida, Hurricane (now tropical depression) Irma left a trail of destruction not seen since Hurricane Andrew hammered the state in 1992. But despite the rising death toll, historic flooding and a ruined power grid that could take weeks to repair, meteorologists say Floridians should consider themselves fortunate.
Because it could’ve been much, much worse.
“We got very lucky,” Jeff Masters, co-founder of Weather Underground in Ann Arbor, Michigan, told Bloomberg. 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 allowed the storm’s powerful eye wall – typically the most destructive area of a hurricane – to ravage Florida’s Gulf Coast.
As Masters pointed out, the storm’s last-minute westward shift away from the biggest population center of sprawling Miami-Dade County caused damage estimates to drop to $50 billion Monday, down from $200 billion over the weekend.
According to Bloomberg, the last-minute shift was caused by a wind pattern known as the Bermuda High.
“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.”
For 10 days, computer-forecast models had struggled with how the Bermuda High might influence the direction of the storm, according to Peter Sousounis, director of meteorology at AIR Worldwide. “I have never watched a forecast more carefully than Irma. I was very surprised not by how one model was going back and forth - but by how all the models were going back and forth.”
Ultimately, Irma landed on the Florida Keys as a Category 4 hurricane with 130 mph winds, then as a Category 3 at Marco Island. It reached the Tampa Bay area as a Category 2. That’s compared with Hurricane Andrew in 1992, which plowed into the east side of Florida as a Category 5.
Even though the worst-case scenario was avoided, Irma may still supplant Andrew as the costliest storm to ever rattle the state.
“With Irma, little wobbles made a huge difference,” said Chuck Watson, a disaster modeler with Enki Research in Savannah, Georgia. With a tightly-wound storm like Andrew coming straight into the state, “a 30-mile wobble isn’t going to matter.”
Still, when it comes to damage, “Irma may bump Andrew,” Watson said. The company’s most recent estimate is for $49.5 billion in Irma costs for Florida; Andrew’s were an inflation-adjusted $47.8 billion.”
Of course, Harvey experienced the exact opposite trend as it devastated the city of Houston and caused a “one-in-a-thousand-year” flood, prompting analysts to raise total damage estimates from around $20 billion before the storm made landfall to, in many cases, more than $100 billion today, as many analytics firms repeatedly upped the expected price tag.
AIR Worldwide, a Verisk Analytics risk modeler based in Boston that was cited by Bloomberg, said Harvey’s price tag for Hurricane Harvey, which struck southeastern Texas on Aug. 25, could end up between $65 billion to $75 billion.
The top spots at the moment are held by 2005’s Hurricane Katrina, at $160 billion, and 2012’s Superstorm Sandy, at $70.2 billion, according to a list compiled by the US National Centers for Environmental Information.
And while many on the left have said that this year’s hurricane season has been supercharged by climate change – a sign that the feared “climate catastrophe” will arrive sooner than scientists expect – Bloomberg notes that many historical storms matched their modern peers on the scale of sheer power.
“Those are modern storms. Simulations based on the paths and powers of some that rammed the U.S. 100 or more years ago show they were far more disastrous, or would be if they arrived today when the population is much more dense and there is far more, and far more expensive, property to destroy.
One hurricane that raked the U.S. East Coast in 1893 was so furious the impact could have added up to $1 trillion. ‘They haven’t really happened in our modern economy,’ Watson said, adding it’s only a matter of time. ‘We have so much stuff and so much infrastructure. Leave all the arguments about climate change aside; we are rapidly moving into that era where we are going to be seeing $50 billion, $100 billion storms, and I will not be surprised when we get to $300 billion.’”
Of course, the next question on meteorologists’ minds is whether Hurricane Jose will pass harmlessly out to sea – as computer models seem to suggest – or possibly turn northward to slam Cape Cod. But as Bloomberg notes, we won’t know the answer to that question for at least another week.