As Milton takes aim at Florida, why is Tampa Bay so vulnerable to hurricanes?
The last time the eye of a major storm like Hurricane Milton hit Tampa Bay, in 1921, the city was a sleepy backwater of a few hundred thousand people. A century later, it is one of the fastest growing metropolises in the United States, with more than 3 million residents, and highly vulnerable to flooding due to climate change. As Milton barrels toward Florida’s Gulf Coast, It strengthened into a Category 5 storm on MondayExperts fear that a century of happiness may suddenly come to an end.
Here’s what you need to know:
The National Hurricane Center predicts storm surge in Tampa Bay and surrounding waters of 8 to 10 feet above normal tidal conditions, and rainfall of 4 to 6 inches as a result of Hurricane Milton.
The entire Gulf Coast of Florida is particularly vulnerable to storm surges. Last week, Hurricane Helenethat made landfall about 150 miles from Tampa in the Florida Panhandle still managed to cause drowning deaths in the Tampa area due to waves about 5 to 8 feet above normal tide level.
“If it had made landfall a little further south and east, it could have been a lot worse,” said Philip Klotzbach, a hurricane researcher at Colorado State University.
The increased risk is partly a result of topography. Florida’s Gulf of Mexico coastline is shallow with a gentle, sloping shelf. The higher ocean floor acts as a barrier that stops the storm’s outflow of water, forcing the ocean to flow toward the coast. That’s the opposite of Florida’s east coast, where the ocean floor suddenly drops a few miles offshore.
“You can have the same storm, the same intensity, the same everything, but very different waves,” Klotzbach said.
A 2015 report from Boston-based catastrophe modeling firm Karen Clark and Co. concluded that Tampa Bay is the most vulnerable place in the US to storm surge from a hurricane, threatening $175 billion in damage.
While Floridians are no strangers to storms, Tampa hasn’t been in the direct path of a major hurricane in more than a century.
During that period, the area has exploded in growth. Tens of thousands of Americans have moved to the area during the COVID-19 pandemic, with many choosing to settle along barrier islands like Clearwater and St. Petersburg overlooking the normally calm, emerald waters of the Gulf. More than 51,000 people moved to the area between 2022 and 2023. the fifth largest growing U.S. metropolitan areaaccording to U.S. Census data.
Long-term residents, after experiencing countless false alarms and near misses, such as Irma in 2017, may also be unprepared for a direct hit. According to local legend, the blessings of Native Americans who once called the region home and built mounds to keep out invaders largely protected the area from major storms for centuries.
MIT meteorology professor Kerry Emanuel said a hurricane in Tampa is the “black swan” worst-case scenario that experts have worried about for years.
“It’s a huge population. It is very vulnerable, very inexperienced and that is a lost cause,” said Emanuel, who has studied hurricanes for 40 years. “I always thought Tampa would be the city we would be most concerned about.”
Lurking in the waves and wind are also the consequences climate change. Rising temperatures due to greenhouse gas emissions have warmed the oceans, led to sea level rise and increased moisture in the air – all key factors that determine the strength of a hurricane and the potential flooding it can cause.
“As a result of global warming, global climate models predict that hurricanes are likely to produce more intense rainfall and a greater risk of coastal flooding due to higher storm surges caused by rising sea levels,” said Angela Colbert, a scientist at the NASA’s Jet Propulsion Laboratory, wrote in a 2022 report.
On Monday, the National Hurricane Center upgraded Milton to a Category 5 storm after it reached an intensity of 75 miles per hour in the past 24 hours. One reason in particular may be the high water temperatures, which act as fuel for the storm.
“Milton’s rapid intensification is incredible,” University of Miami hurricane researcher Brian McNoldy said in an email. “I have been pointing out for months that the Gulf is and is record or near-record warm.”
The researcher noted that, due to rising sea levels due to climate change, Hurricane Andrew’s storm surge would be 7 inches higher today than when that storm hit South Florida 30 years ago.
Officials in the area began issuing evacuation orders Monday for residents of six counties surrounding Tampa Bay, home to nearly 4 million people. Residents of mobile homes, RVs and manufactured homes that cannot withstand winds up to 110 mph (177 km/h) are especially at risk.
Kevin Guthrie, director of the Florida Division of Emergency Management, strongly urged people to leave coastal areas, noting that people who died on barrier islands during Hurricane Ian in 2022 would still be alive if they would simply cross the bridge to the mainland and find shelter.
“Please, if you are in the Tampa Bay area, please evacuate. If they have declared an evacuation order, I beg you, I beg you to evacuate. Deaths from storm surge are 100% preventable if you leave,” Guthrie said.
Almost inexplicably, the storms appear to be bypassing Tampa, with most of the Gulf disturbances passing well north of the city. The last time the Tampa area was hit by the eye of a major hurricane was October 25, 1921. The hurricane had no official name, but is known locally as the Tarpon Springs Storm after the resort town where it made landfall.
The storm surge of that hurricane, estimated at Category 3 with winds of up to 207 km per hour, was set at 3.3 meters. At least eight people were killed and damage was estimated at the time at $5 million.
Now the tourist-friendly area known for its white-sand beaches has grown by leaps and bounds, with an economy estimated to be worth nearly $200 billion. Hurricane Milton threatens to wash away all that development.
___ AP writers Joshua Goodman in Miami and Seth Borenstein in Washington contributed to this report.