For the third time in 13 months, a hurricane is moving through the Gulf of Mexico on a collision course with Florida’s northwest coast, still recovering from recent extreme weather conditions with historic storm surge and dangerous winds stretching hundreds of miles. It threatens a region that is recovering.
But Hurricane Helen, which follows last year’s Hurricane Idalia and last month’s Hurricane Debbie, is no ordinary storm even by Florida standards. Like other high-profile climate change storms in recent years, this storm experienced what meteorologists call “rapid intensification,” accelerating at an alarming pace as it moved through the very warm waters of the Gulf. It is expected that it will become more powerful. As a result, it is poised to make landfall as a Category 3 or 4 storm just days after first forming in the Caribbean. It has also expanded to become one of the widest storms on record, potentially bringing life-threatening winds and rain to inland Tennessee.
Hope Webb, a real estate broker who lives on the waterfront in the state’s sparsely populated Big Bend region, said Thursday she was hunkering down and praying for the best as the storm is expected to make landfall tonight.
“I’m a lifelong resident of this area,” she told Grist. “I have weathered many storms and I believe that God has His arms around us, but this storm is definitely testing our strength.”
Three factors conspire to make Helen a particularly powerful storm. Like other hurricanes, its fuel is warm ocean water, which injects energy into the atmosphere as it evaporates. As Helen migrated through the Caribbean Sea, she fed on very warm ocean temperatures, at least with an increase in minimum temperatures. 300 times more likely due to climate changeaccording to experts. As it continued north toward the Gulf Coast, it gathered an unusual amount of water power. warm and deep — Large pool of high-octane fuel.
Additionally, the region has low wind shear, a term that refers to the tendency for wind to move in different directions and speeds at different elevations. This atmospheric disruption typically lowers the upper limit of hurricane strength. Finally, high humidity is another factor that works in Helen’s favor.
“We continue to have near-perfect conditions,” said Kartik Balaguru, a climate scientist who studies hurricanes at the Pacific Northwest National Laboratory.
The combination of warm deep ocean fuels, high humidity, and low wind shear puts Hurricane Helen on the brink of rapid intensification. Technically, this refers to an increase in sustained wind speed of more than 35 miles per hour within 24 hours. scientists have discovered something dramatic Rapid increase in the number of escalations In recent decades it has moved closer to the coast.
“A clear sign of climate change is that the rate of severe hurricanes is increasing,” Balaguru said. “Storms tend to intensify faster and more rapidly, especially closer to the coast.”
That’s why hurricanes are more dangerous than ever. For example, a coastal city may be preparing for an approaching Category 1 hurricane, only to suddenly find itself in a Category 3 hurricane. The farther a hurricane is beyond the coast, the more powerful it can resist dissipation as it travels over land. and lose their fuel source. Also, as the atmosphere warms, it can hold more moisture, which can cause hurricanes to produce more rain.
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What makes storms like Helen so dangerous to coastal communities is not only the wind and rainfall, but also the storm surge. Hurricane winds push water onto the coast, a dangerous outcome for areas like the Gulf Coast that are already experiencing sea level rise.
The geography of Florida’s west coast makes matters worse. In some beach areas, the sea depth drops off sharply just off the coast, but here depth gradually increases as you move away from the shore. If the water near the coast is deep, the storm surge can be partially absorbed by that depth, reducing its impact on land. But in the shallow waters off the coast of Florida, the water has nowhere to go but to flow directly into coastal areas.
Helen’s eye is expected to make landfall near Tallahassee on Thursday night, but the hurricane’s strongest winds tend to blow in the northeastern part of the storm. For Helen, these winds are also about to hit Florida’s less-developed Big Bend region, which was among the worst hit by Idalia last year. that part of the state located very lowAs a result, storm surges can rush inland, unencumbered by geographic features that would normally provide mitigating factors. Expected waves could reach up to 20 feet in towns like Steinhatchee, just south of where Hope Webb is weathering the storm at her beachfront home. In a statement Wednesday night, the National Weather Service office in Tallahassee called the conditions “catastrophic” and “potentially unsurvivable.”
Further south, the populous Tampa Bay region is also poised to see a record surge after decades of near-miss incidents. “Unfortunately, the shape of the coastline in that area definitely makes it more prone to storm surge accumulation,” said Samantha Nebilitza, a hurricane researcher at the University of Miami. “It kind of flows into Tampa Bay, and there’s really no place for the water to go other than that area.” In many cases, Hurricane Helen break surge record more than 2 feet apart.
As of early Thursday morning, the storm was still hours away from passing over St. Petersburg, but the winds were already starting to pick up and the skies were darkening. Several gas stations in the city’s downtown area are running out of fuel as residents fill up their tanks, and most residents in low-lying areas have prepared their homes for flooding with sandbags, tarps and door sealants. It was being strengthened. Flashing signs reading “High Water Expected” warned motorists to stay away from the shoreline. Counties across the Gulf Coast, including the cities of Tampa and St. Petersburg, issued mandatory evacuations for residents in high tide zones and those living in mobile and manufactured homes. Roads in the coastal city of Clearwater were already experiencing localized flooding.
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Hurricane Helen is a massive storm, with a wind field more than 400 miles across, which will bring rain from the Georgia and Carolina coastlines to Missouri and Arkansas. As of early Thursday, All counties in South Carolina, Georgia, and Tennessee Some type of flood or wind warning was in effect. Forecasters warned of flash flooding in the mountains, especially in Knoxville, Tennessee, and eastern Chattanooga as the storm stalls, as well as dangerous winds that could cause widespread power outages across Georgia. are.
Like a car accelerating faster, Hurricane Helen could head further inland without losing momentum, given how much speed it picked up as it passed through the extremely hot Gulf waters.
“We basically just jump into these states,” Nebilica said. “And at that speed, it’s going to take a lot longer to slow down.”
All these areas, whether coastal or inland, are undergoing significant development that makes them particularly vulnerable to flooding. Florida’s coast has thousands of homes in low-lying coastal areas that are easy prey to storm surge, and states like Georgia and North Carolina have flooded rivers and streams that are likely to flood as Helen passes through. Thousands of homes are being built nearby. As powerful hurricanes like Helen become more frequent, these vulnerabilities are exposed.
“We are entering a new normal that we will experience under climate change,” said Michelle Meyer, director of the Center for Risk Reduction and Recovery at Texas A&M University. “But in addition to that, what has been going on for a long time is that we continue to build in very dangerous places and in very dangerous ways, so we are building more and more in areas that regularly flood. If we continue to add housing and continue to add housing to the coast without requiring greater mitigation measures, the risks will continue to increase.”
Ayurella Horn-Muller contributed reporting to this article.
