Living near the gleaming expanse of Tampa Bay in Florida used to require a certain calculus: Fear the Big One, a powerful hurricane that would tear into the densely populated region and drown people and property. But also rest assured that most Gulf of Mexico storms are near-misses — one has not directly hit Tampa since 1921 — and keep enjoying life on the coast.

Lately, though, the calculus has changed. A rash of Gulf storms in recent years, culminating with Hurricane Helene on Thursday, has given way to a new reality for the booming region’s residents: Hurricanes that remain hundreds of miles away are likely to wreak havoc on the Tampa Bay region, as are smaller storms.

Helene, a Category 4 hurricane, made landfall near Perry, Fla., some 200 miles north of Tampa. It followed a path similar to Hurricane Idalia in August of last year and Hurricane Debby last month. All three storms put wide swaths of the Tampa Bay region underwater, though none more than Helene, which brought storm surge into neighborhoods that had not seen such flooding in decades — or ever.

“I don’t know what to do,” Mimi Wills, a South Tampa resident, said as she pushed open her front door on Friday morning and found more than three feet of water had come in during the storm. “In all the years I’ve lived in Florida, this has never happened.”