How high will Tampa Bay’s tides be when Helene’s storm surge peaks?

Hurricane Helene, expected to make landfall as a major hurricane in Florida’s Big Bend region Thursday, could bring life-threatening storm surge to much of the state’s west coast.

Federal forecasters have issued surge predictions in Tampa Bay higher than the region has seen in recent history.

Researchers say those high-end estimates would occur if Helene sweeps by Tampa Bay during a high tide. But model predictions showed the opposite effect might be in store.

Bob Weisberg, a University of South Florida professor and oceanographer, said the tides are in Tampa Bay’s favor.

Model runs Wednesday showed Helene would stray closest to the region when tides are at their lowest early Thursday evening.

Low tide is expected at 6 p.m. Thursday and will rise overnight before peaking at high tide about 2 a.m. Friday, according to the National Weather Service’s Tampa Bay office.

It could bring water levels roughly six feet above sea level in St. Petersburg, Clearwater Beach and Old Port Tampa south of the Gandy Bridge, according to the college’s Ocean Circulation Lab.

“That’s still pretty high, but we’re lucking out,” Weisberg said.

Storm surge is predicted to be higher than during Hurricane Idalia last year, which brought 3 to 5 feet to the Tampa Bay area just hours before a king tide, one of the highest tides of the year.

But Helene, expected to be a larger storm than Idalia, may come with similarly fortunate timing.

“It’s still going to broach the sea walls, and some streets will still get wet,” Weisberg said. “It won’t be disastrous.”

When storm surge does rush into Tampa Bay, it will push waters to the top of the bay. With nowhere for that water to drain, northern Tampa Bay could experience surge higher than six feet, according to a tide gauge near the Courtney Campbell Causeway Bridge.

With landfall still many hours away, Weisberg said there are still a few concerning “what-ifs.”

“As long as the storm continues advancing at the rate that it’s advancing, then the timing will be OK. My biggest fear is that it slows down,” Weisberg said. “We want the storm to just move real fast and get the hell out of here.”

The storm was moving north-northwest at 10 mph Wednesday afternoon, forecasters said. Helene is expected to gain speed as it barrels toward land.

If Helene slows even a little, it’s possible that surge coincides with high tide instead, Weisberg added. That could bring storm surge closer to the National Hurricane Center’s upper estimate of 8 feet in Tampa Bay.

The hurricane center said Helene’s timing isn’t set in stone.

“It is still too soon at this point to be overly focused on an exact landfall location and time,” forecasters wrote in an Wednesday afternoon update.

Local forecasters at the weather service’s Ruskin office echoed that caution.

Onshore winds, which will push surge toward the coast, are predicted up to 30 mph Thursday night, with gusts up to 60 mph, said Ross Giarratana, a meteorologist with the Tampa Bay office.

“We’re really going to see that big drive of storm surge Thursday night or Friday morning, when the winds go southwesterly. That’ll be when the whole bay really experiences that big push,” he said.

“That’s going to be the window of major concern.”

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