History tells us that the strongest hurricanes to make landfall in the U.S. were often mild tropical storms just a few days earlier, according to the National Weather Service.
Ninety years ago, on Sept. 2, 1935, the Labor Day Hurricane made landfall in the Florida Keys as the strongest hurricane in recorded U.S. history.
It was a tropical storm just three days earlier, but intensified rapidly, eventually reaching sustained wind speeds of 185 mph at landfall.
The nation’s 10 strongest landfall hurricanes in the past 100 years were all tropical storms three days before landfall. That’s “a good reminder to remain prepared when a system heads your way,” the National Weather Service in Miami recently posted on X.
The list of storms includes several that hit Florida:
— Andrew (1992), which hit as a Category 5 storm with maximum sustained winds of 165 mph. Andrew destroyed approximately 49,000 homes and caused 15 direct deaths and 28 indirect deaths.
— Charley (2004), which intensified rapidly just before landfall as a Category 4 storm at Cayo Costa, near Fort Myers. The storm killed 15 people directly and 20 more indirectly.
— Michael (2018), which made landfall as a Category 5 hurricane in the Florida Panhandle with maximum sustained wind speeds of 161 mph. Michael killed 59 people in the U.S. and 15 in Central America.
— Ian (2022), which made landfall at Cayo Costa near Fort Myers at a Category 4 storm with 150 mph winds. Ian was directly responsible for 66 deaths in Florida. Storm surge took 41 lives, and freshwater flooding in central and eastern Florida caused 12 deaths.
According to the National Weather Service, this fast intensification near landfall is common. The average time for a landfall storm to jump to a hurricane is about 50 hours before landfall.
A 2023 study showed that hurricanes are intensifying more rapidly now than in the past.
Globally, the amount of rapidly intensifying hurricanes in coastal zones (within about 250 miles from shore) tripled from 1980 to 2020.
The study attributed the trend to a rise in sea-surface temperatures due to climate change.
Those higher water temperatures fuel hurricanes. Sea-surface temperatures need to be around 80 degrees or higher to spark rapid intensification.
Several factors other than water temperatures allow for rapid intensification, including a storm’s width. Storms with smaller diameters can spin up more quickly. And a storm that has an upright posture is more likely to intensify.
