The forecasters got Hurricane Irma mostly right. At least compared to the predictions of past storms. That’s one of the conclusions from a National Hurricane Center report on the big storm that hit Florida last September.
John Cangialosi is the lead author of the center’s report on Irma.
“We’re not trying to brag here in any sense, but the Irma forecasts we had were really successful. That was very, very low errors that we made for track prediction,” Cangialosi said.
In the future, they won’t always be so successful, he said — that’s why hurricane forecasters and emergency managers keep telling the public not to focus on the exact forecast track or even the wider cone.
“Try to look at what might happen in your area and don’t be overly deterministic if I’m in the cone or out of the cone,” he said. “Every storm will be different, so let’s take these one at a time and please don’t compare systems over time like say, ‘Oh I survived Irma, I’ll be OK with the next one.’ They really are very different.”
The purpose of the report
The National Hurricane Center does a report for every storm. The purpose, Cangialosi said, is to “get the science right.” It also evaluates how well the Hurricane Center did at predicting the storm, and documents the storm’s impacts, in physical damage and death toll.
The report lists 80 indirect deaths and four direct deaths from Irma in Florida. None of those direct deaths took place in Monroe County.
The Monroe County medical examiner lists 17 deaths from Irma, including a man found in rubble in Marathon, a man found in a partially sunken boat off Stock Island and a man found near the shoreline, wearing a life jacket, on Big Pine Key.
Cangialosi said every agency has a slightly different definition of what constitutes a direct or indirect death. For the Hurricane Center, “a direct death means that individual or group of individuals died directly because of the storm. They either drowned due to the storm surge or the rain or they were blown away by the wind. Or let’s say the wind pushed them over and caused them to hit their head or something. So a direct death has to be because of the forces of the storm.”
Indirect deaths are those that are related — like falling off a ladder while putting up shutters or dying in a car accident during evacuation.
The Hurricane Center gets a tabulation from the state and applies its definitions.
“We didn’t have a complete good record in the Keys when we released the report. And I’m working with the Key West forecast office and the FEMA office in Key Largo to maybe revise that,” he said. “There were a lot of what we noted was indirect deaths in the Keys but we’re going to take a another look at that but to make sure that’s right … There could be a revision coming up in the next few weeks.”
Seven landfalls, five as a Category 5
Irma, Cangialosi said, is “one for the history books.”
It was a Category 5 storm, and those are rare in the Atlantic. And Irma was notable for not only her strength but how long she held it.
“Most times when you get a Category 5 hurricane in the Atlantic, it gets to that mark, Category 5, holds it for maybe hours — 12 hours, 18 hours. And then it weakens,” he said. “Irma held it for 60 straight hours. That’s second in history that we know of.”
The only one believed to hold it longer was in 1932 — and that was before satellites existed so the accuracy of the data on that is unknown.
‘I don’t think they realize how lucky they were’
Hurricane Irma and the 2017 season was a “wake-up hurricane season for Florida,” Cangialosi said — the first serious damage since 2005.
“The Keys saw the worst of Irma so I think they have probably the least amount to learn because they experienced it,” he said — noting, though, that Key West was largely spared the worst effects because the track when to the east of the biggest city in the island chain.
But he said the storm should still be considered “a huge warning sign” for Key West and for Southwest Florida.
“They were so lucky — I don’t think they realize how lucky they were,” he said. He’s referring especially to the population centers there, Naples and Fort Myers.
“We thought that they may have been just inundated. They’re very vulnerable to storm surge there,” he said. But storm’s track going inland at Marco Island and staying inland, spared those cities the worst storm surge.
“We really worry about communities like them, because they may think they experienced Irma when they really didn’t,” he said.
Correction: An earlier version of this story misspelled the name of the author of the NHC study. His name is John Cangialosi, not Cangialosa.