Hurricane Milton brought a shocking deluge. The reason why doesn’t bode well for Florida
Published Oct. 2024 in the Miami Herald
Water did much of Hurricane Milton’s damage in Florida — but unlike Helene just two weeks earlier, it wasn’t just from the record storm surge that swept over Gulf Coast beaches and communities. Milton was a massive rainmaker — overflowing canals, rivers and lakes and flooding homes and neighborhoods from North Tampa to Orlando.
Climate change almost certainly made Milton’s deluge worse, scientists found in a new post-hurricane analysis — by perhaps 20 to 30 percent. Its findings don’t bode well for Florida’s future.
“What this report is telling us is that storms like Milton are becoming more likely in the warming climate that we have,” said Shel Winkley, a meteorologist with Climate Central who helped work on the World Weather Attribution’s data-backed, peer-reviewed report.
The downpours from Milton shocked a lot of people who lived well inland, far from evacuation zones. Joanna and Matthew Weddleton, a newlywed couple in Largo, was among them. The couple purchased their ‘forever home’ in August and upgraded it, putting in a brand new roof, vinyl flooring, air conditioner and windows.
They liked that the house was in a friendly neighborhood near the school district where Matthew worked and where they hoped to send their own kids to one day. But above all, they chose the house because it was “inland enough” to be safe from storm surge and flooding. “Or so we thought,” Joanna said with a sigh.
The 12 inches from Milton turned the backyard into a lagoon. Water made its way past the sandbags she anxiously put out the day before and overwhelmed other temporary flood barriers. Then the water started to seep from the floorboards. They came back the next day to a soggy floor, no power, service or gas and a rotting fridge with all grocery stores around closed. Joanna described it as “literal hell.”
Days later, they ripped out the floorboards and found mold. Now, hopping from hotel to hotel they are unsure when their life plans will get back on track, they posted on GoFundMe. “My goal was to save up 10K before we have kids. We’ve already spent it this week, so it’s probably going to be another, like, four years — if at all,” Joanna said.
A WARMER WORLD IS A WETTER WORLD
Scientists are still sorting through the impacts of climate change on hurricanes, which have been around forever and act as a natural cooling system for ocean heat. Extreme hurricanes happened long ago and some of the strongest on record date back 100 years or more.
But climatologists say human-driven climate change is having increasing effects with hurricanes operating in an environment where the sea level is higher, temperature in the Atlantic Ocean and Gulf of Mexico — two prime breeding grounds — are warmer and the air holds more moisture. Those are all perfect ingredients for stronger, wetter and potentially more damaging storm.
A warmer world is a wetter world, said Matthew Cappucci, an atmospheric scientist and senior meteorologist at MyRadar.
“Picture a sponge that can hold a little bit more water. When you step on that sponge, it’s going to squeeze out more water,” Cappucci said.
Jared Rennie, a research meteorologist at National Oceanic and Atmospheric Administration in Asheville, N.C. — which itself suffered catastrophic flooding from Helene — created and shared a map with the Miami Herald showing preliminary rainfall estimates from Milton and how they were classified as rare precipitation.
Rennie’s preliminary analysis showed that about an area of some 850 square miles, mostly along the I-4 corridor in Central Florida, experienced what NOAA calls a one-in-100-year rainfall event. Some areas experienced the amount of rain expected only once every 200 years. During Milton, Rennie said, the rainfall over 24 hours added up to about what the area would expect to see over 5 entire Octobers.
Such meteorological milestones are, of course, estimates based on past records that can occur more often. And with climate change that seems increasingly to be the case. Two experts the Herald spoke to cited a quote from Emil Gumbel, considered a founding father of what’s called extreme value theory, who famously said, “It’s impossible that the improbable will never happen.”
While its still unclear if climate change will create more storms, scientists say there is plenty of evidence that is making storms more intense. That means when hurricanes do choose to form, they tend to sway towards bigger Category 3, 4 or 5 storms, said David Keellings, a researcher studying climate extremes at the University of Florida. Milton, in the days before it made landfall, ramped up its intensity at a near-record clip.
At one point but barometric pressure, a key measure of intensity, is was the fourth strongest hurricane on record. The impact on rainfall is been evident for decades. Keellings found that rainfall during Hurricane Maria in Puerto Rico in 2017 was five times as likely because of climate change than without climate change. “Hurricanes are more intense, they’re wetter and seem to be moving at a slower pace,” Keellings said.
How a storm forms, its path, and how it is steered by atmospheric processes makes every hurricane unique. So if the next hurricane doesn’t have as extreme of rainfall as Milton, that doesn’t mean the climate isn’t warming. “We can be assured that we’re going to have the potential for more intense storms and more extreme rainfall events, but it doesn’t mean we’re going to have them every year,” said Tom Frazer, dean of the College of Marine Science at the University of South Florida and executive director of the Florida Flood Hub for Applied Research and Innovation.
INLAND FLOODING IS A HIDDEN DANGER
The widespread inland flooding comes from what are known as rain bands that swirl around the powerful eye of a hurricane. They can extend hundreds of miles from the central core, sweeping storms heavy with rain across huge areas. But where that rain will fall isn’t always easy to predict.
Haiyan Jiang, an observational meteorologist at Florida International University, said satellites give about a one-day heads up on how strong the rainfall is in a specific location at the current time — thus can become a challenging task to safely issue evacuations for inland regions. “We cannot predict the exact location of where and how much the rainfall will be further inland or where will get the strongest rainfall,” Haiyan Jiang said.
That can be dangerous, even deadly, in places not expecting flooding like western North Carolina around Asheville, where Hurricane Helene dropped nearly 14 inches that engorged rivers and drowned towns, causing more than 100 deaths. More than 50% of the deaths that occur during hurricanes come from inland freshwater flooding, outweighing that of surge, wind or tornados, according to the National Weather Service While some communities are known flood risks, the massive rainfall from hurricanes can cause damage in areas that are even outside of FEMA flood zones.
A representative who did not want to be identified from the full-service repair company, SERVPRO, said they were surveying homes in non-flood zones hit by the rain bands and fresh water flooding in the North Tampa area. The week before they were in the southern region ripping up floorboards from storm surge. He said from what he’s seen in hundreds of homes and businesses alike is drainage issues with nowhere for the water to go.
“We have really good models that show how high the surge will be,” Keellings, the UF climate extremes researcher said. “We don’t do just as well with predicting exactly where and how much the rainfall will be further inland. So there’s people that are further inland that are thinking, oh, I’m okay. I’m not by the coast. But really, you may not be okay because of the rainfall and flood threat.”
That’s just what Heidi Everley and Brittany Hyman thought in their home in the Disston Heights neighborhood in St. Petersburg, five miles away from the city pier. The city saw record rain, a stunning 1 in 1000-year event of more than 18 inches in 24 hours. Cappucci, the atmospheric scientist, said 5.09 inches of rain fell in a single hour and more than nine inches in three hours. The typical drainage system in Florida is designed to handle about six inches over 24 hours. Things were made worse because prior to Milton, the ground was already saturated from Helene and other rainfall, said USF’s Frazer.
With so many impervious surfaces such as roofs, roads, parking lots and sidewalks, all that rain pile up. Its also flows out of the overwhelmed stormwater systems, pipes, swells, canals and retention ponds. “All of those systems are designed to hold a certain amount of water based on historical data,” Frazer said. “What we have had recently is extreme events that essentially surpass the capacity of the stormwater system.”
That’s what happened in Disston Heights. Everley and Hyman’s home was filled with two feet of rain and murky sewage water. Lost in the mess were yearbooks, letters and all sorts of irreplaceable memories — ruined photos of Hyman’s late father and her 16-year-old dog, Tucker who recently died. “We didn’t think about the flooding at all. We lost everything,” Hyman said. “We had everything on the ground, nothing was raised. This was like a shell shock to us in our entire community. Nobody thought this was going to happen.”