Hurricane Lee charts a new weather path, and could mean more big storms

Hurricane Lee is rewriting the old rules of meteorology, leaving experts amazed at how quickly it became a massive Category 5 hurricane.

Experts say Lee — which quickly dropped to a still-dangerous Category 3 and held that strength on Saturday — could be a harbinger of rising ocean temperatures, spawning fast-growing major hurricanes that could threaten communities far north and inland.

“Hurricanes become stronger at higher latitudes,” said Marshall Shepherd, director of the Atmospheric Sciences Program at the University of Georgia and former president of the American Meteorological Society. “If this trend continues, it will highlight places like Washington, D.C., New York and Boston.”

Hypercondensation

As ocean temperatures rise, they act as jet fuel for hurricanes.

“This excess heat will re-emerge at some point, and one of the ways that this happens is through stronger hurricanes,” Shepherd said.

During the overnight hours of Thursday, Lee broke the benchmark for what meteorologists call rapid intensification — when a hurricane’s sustained wind speed increases by 35 mph (56 km/h) within 24 hours.

“This increased speed by 80 mph (129 kph),” Shepherd said. “I can’t stress this enough,” said Shepherd, who describes what happened with Lee as hyperintensification. “We used to have this gauge of 35 miles per hour, and here is a storm that was twice that amount, and we see that happen frequently.” “.

With extremely warm ocean temperatures and low wind shear, “all the stars lined up to condense rapidly,” said Kerry Emanuel, professor emeritus of atmospheric sciences at MIT.

Internal threats

Category 5 condition, when sustained wind speeds are at least 157 mph (253 km/h), is very rare. Only about 4.5% of named storms in the Atlantic developed into Category 5 in the past decade, said Brian McNoldy, a scientist and hurricane researcher at the University of Miami.

More intense major hurricanes also threaten communities inland, because monster storms can grow so powerful that they remain dangerous hurricanes for longer distances above land.

“I think that’s a story that’s been somewhat untold,” Shepherd said. “Because these storms are powerful when they make landfall, in some cases they move fast enough that they remain as hurricanes inland.”

Hurricane Idalia was the most recent example. It came ashore in the Florida Panhandle last month and remained a hurricane as it entered southern Georgia, hitting the city of Valdosta more than 70 miles (116 kilometers) from where it made landfall. At least 80 homes were destroyed in the Valdosta area and hundreds more were damaged.

In 2018, Hurricane Michael took a similar path of inland devastation, destroying cotton crops and pecan trees and leaving widespread damage across southern Georgia.

Monster waves

Although it is too early to know how close Lee will approach the East Coast of the United States, New Englanders are watching the storm warily. As it gets closer, it may bring rising sea levels and rip currents up and down the East Coast.

“What we will see from Lee — and we are very confident — is that it will be a major wave producer,” Mike Brennan, director of the National Hurricane Center, said at a news conference on Friday.

On Saturday, big waves hit the northeastern Caribbean Sea as Lee made his way through open waters hundreds of miles off the northern Leeward Islands.

“This morning, the highest significant wave height we were analyzing in Lee was between 45 and 50 feet, and the highest waves can be twice that,” Brennan said, speaking of waves far offshore. “So we could be looking at 80- or 90-foot waves associated with Lee.”