 Track of Florence, according to the Saffir–Simpson scale | |
| Meteorological history | |
|---|---|
| Formed | August 31, 2018 |
| Extratropical | September 17, 2018 |
| Dissipated | September 18, 2018 |
| Category 4 major hurricane | |
| 1-minute sustained (SSHWS/NWS) | |
| Highest winds | 150 mph (240 km/h) |
| Lowest pressure | 937 mbar (hPa); 27.67 inHg |
| Overall effects | |
| Areas affected |
|
Part of the 2018 Atlantic hurricane season | |
The meteorological history of Hurricane Florence spanned 22 days from its inception on August 28, 2018, to its dissipation on September 18. Originating from a tropical wave over West Africa, Florence quickly organized upon its emergence over the Atlantic Ocean. Favorable atmospheric conditions enabled it to develop into a tropical depression on August 31 just south of the Cape Verde islands. Intensifying to a tropical storm the following day, Florence embarked on a west-northwest to northwest trajectory over open ocean. Initially being inhibited by increased wind shear and dry air, the small cyclone took advantage of a small area of low shear and warm waters. After achieving hurricane strength early on September 4, Florence underwent an unexpected period of rapid deepening through September 5, culminating with it becoming a Category 4 hurricane on the Saffir-Simpson scale. Thereafter, conditions again became unfavorable and the hurricane quickly diminished to a tropical storm on September 7.
From September 7–9, Florence's forward momentum slowed as it turned west. Favorable conditions again fostered intensification on September 9 and the system regained hurricane status. Turning northwest toward the United States, a second phase of rapid intensification ensued that day into September 10 with Florence regaining Category 4 strength. It subsequently reached its peak intensity with maximum sustained winds of 150 mph (240 km/h) and a pressure of 937 mbar (hPa; 27.67 inHg). Steady weakening occurred over the following days as steering currents began to collapse. The hurricane slowed to a crawl by September 13 as it approached North Carolina. Torrential rains began affecting the state on this day and persisted through September 17.
Florence made landfall near Wrightsville Beach on September 14 with winds of 90 mph (150 km/h). With the system remaining close to the coastline it weakened slowly, eventually degrading to a tropical depression on September 16. Training rainbands produced prolific, record-breaking rainfall across North and South Carolina throughout this period. Catastrophic flooding and extensive wind damage ensued, resulting in 22 direct fatalities and 30 indirect deaths across the Carolinas and Virginia.[1] Florence later transitioned into an extratropical cyclone on September 17 before dissipating the following day.