Here’s why so many storms have turned away from Florida. Will our luck continue?

The Atlantic hurricane season has been very active this year, but most of the tropical storms and hurricanes have veered north as they crossed the Atlantic, carrying them away from Florida’s east coast.

There are a few key factors that have kept Florida’s east coast safe this year, but those factors could change as we head into October.

How many storms have tracked north?

Out of the 17 tropical systems this year thus far, almost all have steered north before reaching the east coast of the U.S., and models show that Tropical Storms Philippe and Rina, currently traveling west, will do the same. For most of the storms coming off the coast of Africa — the classic pattern for summer — that meant spinning off into the Atlantic (aka a “fish storm”).

A few made landfall, though. Hurricane Idalia began off the Yucatan, so its northerly path took it into Big Bend, and Tropical Storm Ophelia formed off Florida’s east coast and headed north into North Carolina. Franklin’s right-hand turn sent it into the Dominican Republic, and Lee’s arc north took it away from the Bahamas on up to Canada.

Only Bret and Harold managed to keep a westly path. Bret fizzled and Harold rolled into South Texas.

Unique 2023 steering forces

Tropical storms coming off Africa, as strong as they are, get pushed around by large atmospheric forces.

Those forces include the Bermuda or Azores High, a large persistent high-pressure center that forms every year over the North Atlantic and shifts east and west, depending on the season.

The Bermuda High sits over the north Atlantic and acts as a boundary that won’t allow storms rolling west off Africa to move north, thus sending them west. “It keeps storms south until they reach the end of the high,” said WFLA meteorologist Jeff Berardelli. Then they round the edge of the high and head north.

Where the Bermuda-Azores High is located changes every year. “Sometimes it extends way west toward Florida and toward the eastern U.S.,” Berardelli said. “In that case, the storms are steered either into the Caribbean, or into Florida’s east coast. This year, the high is a little weaker, and the position is a little farther east, so the storms have been recurving, like Franklin and Lee,” he said.

Another steering force this year has been a semi-permanent trough, or low, sitting over the east coast like a guardian. This trough  typically shifts east and west, but for some reason it’s been sitting over the east coast this year. “It blocks the hurricanes from going to the U.S.,” said National Weather Service meteorologist Will Redman. “It acts as a blocker.”

Berardelli said that Tropical Storms Philippe and Rina, which tracked across the Atlantic toward the Caribbean, will be affected this way.

“As the systems encounter (the trough sitting over the east coast), closer to the Leeward Islands, they’ll start to feel that and they’ll stop. They won’t be able to go much farther west than that.”

That’s all well and good for Florida if the storms originate off Africa, but that’s about to change.

October shift

The northern steer has been affecting storms crossing the Atlantic from Africa, near Cape Verde. “We’re now at the end of the Cape Verde season,” Berardelli said. “In October, storms typically form in the Caribbean.” Idalia’s general path from off the Yucatan and into the Gulf is a classic October route, even though it occurred in August.

Autumn means that a dip in the jet stream typically replaces any trough over the east coast, Berardelli said. “The real jet steam gets stronger at this time of year and starts dropping south. We’re going to be seeing a lot more of that over the coming weeks.”

The jet stream will act as a barrier, just as the 2023 trough did, pushing storms north, but the storms will begin forming in new areas, specifically the Caribbean, farther south.

A northern track from the Caribbean puts Florida in the crosshairs. “This is definitely the dangerous time of year for the west coast of Florida … down through Fort Myers and the Florida Keys,” Berardelli said.

But the east coast is included in the danger zone. The Category 3 Hurricane Wilma, which barreled across southern Florida from west to east in October of 2005, is a great example, said Berardelli. Wilma carried its power to the east coast — top winds in Fort Lauderdale were 99 mph, and 101 mph at Palm Beach International Airport.

El Niño effect

El Niño is a weather pattern occurring every two to seven years that sees warm water pile up in the Pacific along the coast of Central and South America. They can affect weather globally. An atmospheric ripple-effect is strong wind shear over the Atlantic and Caribbean, which topples hurricanes. But this year has been unique.

“We should have seen a lot of wind shear in the Caribbean this year because of El Niño,” Berardelli said. “But this year, it’s actually been quite the opposite. Wind shear across the Caribbean has been significantly below normal.”

In a normal El Niño year, the Pacific is so much hotter than the Atlantic that a pressure pattern creates strong shear across the Atlantic. Berardelli says that this year, the Atlantic is too hot for that to happen. “It’s warmer, in many cases, than the eastern Pacific. And so it has basically stopped that effect, which is not good for the Atlantic hurricane seasons if it continues going forward. Without the shear, you end up with more storms and stronger storms.”

He said that the El Niño is currently strengthening, so it’s conceivable that its shearing effects might pick up later in the season. “But I don’t think it’s a guarantee,” he said.

As for the Caribbean, sea surface temperatures are extremely high, so there’s plenty of energy for a storm to use if one forms “but so far we don’t see anything on the longer-range computer models for the next week and a half at least,” Berardelli said.

“Every year is a different pattern. Sometimes it gets stuck. We’ve had a stuck weather pattern across Florida, this weird westerly steering flow.”

This hurricane season has been an odd one, with the weak Bermuda high, the persistent trough guarding the east coast and the lack of shear from El Niño. “There will be a lot of studies (focusing) on this year,” Berardelli said. “A lot of it has to do with record hot ocean temperatures. They’re not just above normal, they are obscenely above normal. And such weird weather patterns are emerging, too — how you connect the two is where research belongs.”