Source:  Corey Davis, NC CLIMATE OFFICE, 9/18/18


It was a storm that briefly appeared set to threaten all of North Carolina's records for landfalling hurricane intensity. In the end, Florence was weaker but wetter than initially expected, and between the storm surge, extreme rainfall, and unprecedented inland flooding, the stubborn storm still left a record-breaking mark on our state.

Storm History
Florence was the sixth named storm to form in an initially quiet start to the 2018 hurricane season. Cool water across the eastern Atlantic and strong wind shear over the Caribbean Sea inhibited storm development from June through August.

The onset of the climatologically most active month in the tropics brought increasing and above-normal sea surface temperatures off the US east coast, and a surge of five storms developing in a two-week period. Florence was the first of those, becoming a tropical depression just after it emerged off the African coast on August 31.

As Florence rapidly strengthened from a Category 1 to a Category 4 in just 24 hours beginning on September 4, it was also drifting to the north into an area of higher wind shear, which ripped the storm apart just as quickly and brought it back down to tropical storm status.

Forecasts models wrestled with whether Florence would turn north, following a weakness in an upper-level ridge, or continue its track toward the US east coast. Once it became clear that the storm would target the Carolinas, Florence became better organized, restrengthening into a Category-4 monster with maximum sustained wind speeds peaking at 138 mph.

If it maintained that intensity, Florence would have rivaled Hurricane Hazel as North Carolina's strongest landfalling storm on record. It also achieved such strength unusually far north. Florence was well outside the so-called Hebert boxes we defined for North Carolina that show the typical trajectories of landfalling storms.

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