All the damage done in Miami-Dade and Broward — the downed trees and power lines, sunken boats, torn away roof shingles and power outages — were likely caused by something less than hurricane winds.
While the readings from the National Weather Service in Miami are preliminary, they show Hurricane Irma raked both counties with gusts easily topping hurricane strength. But by the technical measurement of hurricane categories — wind speed sustained for one minute — coastal southeast Florida endured what amounts to a very strong tropical storm.
That’s less than a sustained 74 mph wind. Around Irma’s eye at landfall in the Lower Keys, sustained winds were estimated at 130 mph, Category 4 power. And the Keys clearly got walloped much worse than the mainland. One gust of 120 mph was recorded at Big Pine Key before a power failure halted the readings.
The top gust in Miami-Dade, recorded both at Miami International Airport and Key Biscayne on Sunday, was 99 mph. That’s equal to a Category 2 hurricane. Sweetwater saw 96 mph, Belle Meade 92 mph and Coral Gables 90 mph. The highest recorded wind gust in Broward County, the National Weather Service said, was in Deerfield Beach where it reached 86 mph.
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While Miami-Dade and Broward avoided the strongest core of the storm, Irma’s wind field was so large and the pounding so lengthy that the wind damage still proved extensive. And that doesn’t even factor in the storm surge pushed into downtown Miami and other coastal areas that continued as far north as Charleston as Irma marched north.
“The gusts are what cause the damage,” said Shahid Hamid, a Florida International University professor who studies hurricane. “Given the fact that we were so far away from landfall, we received more damage than expected. The duration of the storm was also much longer than we’re certainly used to.”
Andrew Hagen, a meteorologist with the National Weather Service in Miami said though the agency is still gathering information and it’s too early to be specific, it’s safe to say most of Miami-Dade sustained tropical force winds of between 55 and 70 mph.
“A lot of metro areas in Miami-Dade and Broward got fairly similar wind speeds,” Hagen said. “Everyone had hurricane-force gusts.”
The highest recorded wind speed in the state was in Naples, where Irma landed and where a gust delivered by Irma came in at 142 mph. In Marco Island, where Irma made a second landfall after passing through the Keys, a gust of 130 mph was recorded.
The Florida Keys may have been the hardest hit area in all of South Florida — but as of Tuesday, that wasn’t for certain.
That’s because the last wind speed recorded by the National Weather Service in Key West showed gusts that reached 120 mph in Big Pine Key, 92 mph in Key Largo and 91 mph in Key West.
It was 8 a.m. on Sunday. Then the power went dead and those were the last numbers received from the Keys. More readings will become available as researchers review data from individual weather stations.
Forty minutes later Irma made landfall 20 miles north of Key West at Cudjoe Key as a Cat 4 storm with 130 mph, according to the National Weather Service.
Irma’s highest gusts
The National Weather Service in Miami has released a preliminary list of some of the highest wind gusts recorded as Hurricane Irma crossed the Florida Keys and moved north along the Southwest Florida coast:
142 mph: Naples
130 mph: Marco Island
120 mph: Big Pine Key (before readings stopped ahead of landfall)
99 mph: Miami International Airport and Key Biscayne
96 mph: Sweetwater
92 mph: Belle Meade, Coral Gables
86 mph: Deerfield Beach