The glittering new high-rises that have gone up across South Florida offer one amenity not mentioned in sales brochures: The opportunity to experience the fiercest winds of any hurricane.
Wind strength increases dramatically with just a few hundred feet of altitude, meaning a lesser storm at street level can pack a much harder punch to the penthouse suite.
Since South Florida’s last direct hit in 2005, when Hurricane Wilma swept across the state, the number of high-rise buildings has multiplied, altering the skylines of Fort Lauderdale, Miami, Hallandale Beach, Miami Beach and other cities. Constructed to the toughest building code of any state exposed to hurricanes, they are unlikely to suffer significant structural damage from even the strongest storms, experts say. But that doesn’t mean they are a good place to stay in a hurricane.
Buildings will sway, and you’ll feel it. Windows will flex in and out, some breaking in the strongest storms and sending lethal shards through living rooms and bedrooms. Water will penetrate even the best-constructed buildings, threatening to soak thousands of dollars of flat-screen TVs, carpeting and artwork. When it’s over, with elevators dead from lack of electricity, residents of upper floors could find themselves marooned in their palaces in the sky.
“They’re not a very safe place of refuge, especially the way we build them today, with all the glass from floor to ceiling,” said Frank Rollason, emergency management director for Miami-Dade County, where dozens of new high-rises have gone up. “If the glass gives way, you’ve just got an open wall of wind and rain.”
Hurricane season officially begins Tuesday and runs through Nov. 30. Although Florida may get through the next six months without anything worse than a close call, most forecasts call for an above-average season , raising the odds of a Florida landfall.
If that does happen, the winds hitting the upper floors of high-rises could be the strongest anyone experiences. A NOAA study of 17 hurricanes found that wind speed in the eyewall rises sharply with altitude. A hurricane that produces 100 mph winds at three stories will produce 115 mph winds at 20 stories and 121 mph winds at 40 stories, ascending from a low-end Category 2 storm to one with the Category 3 force of a major hurricane.
When Hurricane Katrina struck South Florida in 2005, Tamara Oyarzabal and her then-husband decided to ride it out on the 30th floor of their building in Miami’s Brickell neighborhood. Bad call.
“The wind started howling, and the rain started coming in horizontally,” she said. “It started coming in under the sliding doors and it flooded ankle-deep in the apartment. The power went out, and the howling winds made it very difficult to speak.”
“The windows – the actual glass – was bent to the point where I didn’t know glass could bend that far. I was expecting it to break. This went on from like 6:30 to like 2 in the morning. It wasn’t pleasant. My ex-husband was filling up buckets of water and emptying it into the bathtub, trying to get the flooding to go down.”
Although the buildings will sway only a few inches, that’s enough to be distinctly noticeable.
“You’ll feel the building moving around,” said Anne Cope, chief engineer for the Insurance Institute for Business and Home Safety, which advocates better preparation for natural disasters.
Occupants may be tempted to gaze out the window and experience a unique view of nature’s fury. But that would be a mistake. Although windows of new South Florida high-rises must meet stringent impact standards, including glazing to prevent them from shattering, experts say the strongest storms could still break them.
“You can’t be near windows because windows can break and debris can fly around and break even strong windows,” said Kurtis Gurley, professor of civil and coastal engineering at the University of Florida’s Herbert Wertheim College of Engineering . “So interior rooms in a high-rise, from a life-safety perspective, are a good place to be.”
Even if a window doesn’t break, “it will make you uncomfortable,” Cope said. “That window is going to be moving around, making noise, flexing in and out, and you will very likely get a lot of water coming in as the windows are flexing in the wind.”
Although modern construction standards will protect the building’s integrity, Cope said it’s still difficult to keep out water driven by hurricane-force winds through openings along windows or sliding glass doors.
“Water intrusion in high-rise buildings is something people have to be prepared for,” she said.
How can you tell if your building was constructed under the latest and greatest building codes? If it was built in 2002 or later, you should have the best or close to it, since the code gets updated every three years. If your building was built before then, it likely does not meet highest standards unless it was damaged by a storm and had to be upgraded.
After Hurricane Andrew in 1992 mowed down entire blocks of cheaply built houses, Florida adopted a statewide building code that has become a national model. So when Hurricane Wilma struck Fort Lauderdale state 13 years later, new downtown buildings, such as the 42-story Las Olas River House, held up well. Older buildings constructed before the building code sustained severe damage , their facades shredded and windows smashed.
High-rise buildings may seem to reliable offer protection against flooding. But emergency officials in South Florida say they can provide the illusion that it’s safe to ignore evacuation orders.
South Florida’s hurricane evacuation zones are drawn to address the threat of storm surge, the wind-driven increase in sea level that inundates coastal neighborhoods and that accounts for more deaths than high winds.
High-rise residents often ignore evacuation orders, however, thinking that flooding from the ocean won’t be an issue on the 20th or 30th floor.
“A lot of people think because they’re on upper floors they’re going to be safe from storm surge,” said Rollason, Miami-Dade County’s emergency management director. “I’ve had conversations with condo associations, and their intent is to stay. The building’s not going to come down, and that’s probably true. But you’re talking about tons of water, and then the aftermath of being in a building that has no electricity.”
Many residents don’t realize that building generators typically run only emergency systems, such as lighting, alarms and fire pumps, he said. They won’t run elevators or air conditioning.
“You could be stuck there for days with no water, no food, no electric,” he said. “If you’re in an evacuation zone, I don’t care what kind of home you’re in, you should be leaving.”
This season’s prediction from the National Oceanic and Atmospheric Administration calls for six to 10 hurricanes, with three to five achieving major hurricane strength, which means winds of 111 mph or higher. One ominous trend, which scientists say could reflect the impact of climate change, is the unusual number of Category 5 storms produced over the past few years. Since 2016, there have been six of these monster storms, which produce winds of at least 157 mph.
David Fleshler can be reached at dfleshler@sunsentinel.com and 954-356-4535.
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