Preparedness

Bigger, Wetter, Costlier: Studies Suggest Trend of Slower, Wetter Hurricanes as County Reviews Lessons Learned

A June article in National Geographic cites two recent studies that suggest storms are moving more slowly and carrying more water and could continue to do so in the future.

by Jared Keever, The St. Augustine Record, Fla. / July 9, 2018
Flooding from Hurricane Irma. AP/Skip O'Rourke

(TNS) - The morning of Sept. 12, Nick and Bonita Colbert hiked up Flagler Estates Boulevard, through thigh-high waters and carrying an empty cooler between them with their sandals stacked on top.

"It will take days for this to go down," said Hal Baughman as he surveyed the flooding.

Baughman, a friend of the Colberts, had driven down to the edge of the water to give them a lift out to a local convenience store so they could grab more supplies.

As the couple made it to dry ground, they stopped to talk a little about what they experienced riding out Hurricane Irma on a family member's property.

The property was flooded, Nick's car had five inches of water inside it, but the house, a manufactured home that was elevated, didn't see any water inside.

That turned out to be the case for many of the homes in the Flagler Estates community, though reports began to trickle out of damage to the insulation and ductwork under many of those homes.

Baughman said he had lived in the area for years, but had never seen it as bad as he did that morning.

Yet officials, both local and national, are warning that it all could have been worse.

"That's an important part of our message," St. Johns County, Fla., Emergency Management Director Linda Stoughton told The Record last week. "We are really trying to stress, 'It could have been so much worse.'"

And that's not to say it wasn't bad for Irma, or Hurricane Matthew less than a year before that.

"I've got friends using jon boats and canoes to get around," Baughman said on that first full day of recovery after last year's storm.

Officials reported that day that when Deep Creek, a tributary of the St. Johns River that runs through Flagler Estates, overran its banks, the water extended out four to five blocks on either side.

In Hastings the Coast Guard, National Guard and St. Johns County Fire Rescue staged boats and other equipment between Main Street and Morrison Road, preparing to head in to the flooded areas and help those trapped by the water.

By that Tuesday afternoon, Fire Rescue reported they had rescued 17 people and seven dogs from homes in the community.

There were plenty of problems elsewhere in the county. Homes along the St. Johns River flooded. A tornado touched down near Matanzas Inlet, splintering condos at the Summerhouse Beach and Racquet Club. And, less than a year after Hurricane Matthew, there was flooding, again, in St. Augustine's Davis Shores and along the Matanzas River. There was more erosion along Vilano Beach and points north, with at least one home finally succumbing to the depletion of sand and falling onto the beach below.

And as bad all of that was, none of it was the result of a direct hit.

Hurricane Matthew, Stoughton often reminds people, ran up Florida's coast but stayed out to sea and was 31 miles offshore by the time it made it as far north as St. Johns County.

Irma, the most powerful storm on record, passed to the west and brought only tropical storm force winds to the area after running north through the state and devastating much of southern Florida.

"We have not had a direct hit in St. Johns County since Dora in 1964," Stoughton said.

And yet Stoughton can rattle off plenty of problems from the last two storms.

Matthew? Even though the center of the storm was well out to sea, we had a 7-foot storm surge.

Irma? Though sapped of much her strength by the time she made it to northern Florida, the troublesome northeastern quadrant of the storm still gave us the tornadoes and dumped plenty of rain.

A different kind of storm

That Matthew and Irma were similarly destructive but distinct in the threats they presented is not lost on Stoughton, who routinely says that each storm is different and presents its own challenges. Some bring severe flooding, either from rain or storm surge. Others, like Hurricane Andrew, which leveled parts of South Florida in 1992, are primarily wind events.

And this year, during their annual hurricane preparedness exercise at the county's Emergency Operations Center, county officials got to work through another type of storm, a fictitious one called Noah.

"The basis for Hurricane Noah was Harvey, what they experienced in Hurricane Harvey," Stoughton said referring to the 2017 hurricane that, with its days of rain, caused devastating flooding in Houston, Texas.

Noah, in the exercise, essentially parked over St. Johns County for four days and dropped 40 inches of rain on the area. Although the scenario had it weaken to a tropical storm as it lingered, the exercise let officials work though a number of potential problems a similar storm could bring.

Given what some experts are saying it was probably a worthwhile exercise.

A June article in National Geographic cites two recent studies that suggest storms are moving more slowly and carrying more water and could continue to do so in the future.

One, written by James Kossin, with the National Oceanic and Atmospheric Administration's Center for Weather and Climate in Madison, Wisconsin, and published in the journal Nature, found that the forward speed of tropical cyclones had decreased globally by 10 percent over the period of 1949 to 2016. That, the study said, "is very likely to have compounded, and possibly dominated, any increases in local rainfall totals that may have occurred as a result of increased tropical-cyclone rain rates."

"Nothing good comes out of a slowing storm," Kossin told National Geographic. "It can increase storm surge. It can increase the amount of time that structures are subjected to strong wind. And it increases rainfall."

The other study, published in May in the Journal of Climate, by a team led by Ethan Gutmann, with the National Center for Atmospheric Research in Boulder, Colorado, suggested that storms in a world warmed by climate change could be slower, wetter and costlier.

For that study Gutmann and his team plugged data from historical storms into computer models modeling a warmer climate to see what they might look like in the future.

"In one example, Hurricane Ike — which killed more than 100 people and devastated parts of the U.S. Gulf Coast in 2008 — could have 13 percent stronger winds, move 17 percent slower, and be 34 percent wetter if it formed in a future, warmer climate," read a May release about the study from the National Science Foundation.

"Our research suggests that future hurricanes could drop significantly more rain," Gutmann said in that release. "Hurricane Harvey demonstrated last year just how dangerous that can be."

Stoughton said those studies or the trends they suggest aren't what motivated the county to run through a Harvey-based scenario. That, she said, was done primarily out of a desire to put the county's response to a deeper test after two years worth of previous drills and two previous storms.

They learned a lot, both about what problems they might see and how to handle them.

"Transportation proved to be one of our biggest challenges," Stoughton said.

The fictitious storm, settled in over the county for days, kept beating the area with tropical storm force winds and was unrelenting with the rain. That made it particularly difficult getting resources to, and people out of, the harder hit areas.

Neighborhoods and roads flooded, cutting off supply and rescue routes. Officials couldn't open the bridges, not only because of the winds but because the access to those bridges were also flooded. Emergency shelters filled to capacity and at least one had to deal with flood waters creeping under exterior doors, threatening those inside. A sinkhole opened up outside Flagler Hospital.

A storm like that would almost undoubtedly flood Flagler Estates and bring far more property damage than Irma.

Stoughton said she hadn't seen Irma-level flooding in that community since Tropical Storm Gabrielle, in 2001, dropped 10 to 15 inches of rain on the area.

That the community flooded in Irma wasn't necessarily expected. Situated in Evacuation Zone F, they weren't under a mandatory evacuation, though much of the town of Hastings, which sits in Zone A, was.

Stoughton said part of that is because the evacuation zones are based primarily on expected storm surge and not rainfall.

"That wasn't storm surge," she said of the Flagler Estates flooding.

The flooding there, which, because of Irma's south-to-north path, dropped rain along the entire length of the St. Johns River, was exacerbated not only by drainage problems in Deep Creek, but also by ground that was already saturated before the storm hit — a reminder that each storm presents its own challenges.

Officials will use the "ground truth" taken from Irma as they review the evacuation zones to see if changes need to be made, according to Stoughton.

"It's in the process right now," she said.

But it is a meticulous process, she explained, and is done with a great deal of deliberation.

"We don't really have a time frame because we have to get it right," she said. "We have to really look at the science."

In the meantime, Stoughton and her team continue to push their message of "prepare for the worst, hope for the best."

She said that after two recent hurricanes she is heartened to hear people planning for the coming season. Just recently, she said, she heard some people mention that they were planning to use last year's supply of bottled water to keep people refreshed during a Fourth of July party, only so they could replenish their emergency supplies with fresh water for this year.

"It shows that we are experienced," she said.

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