1856 Last Island Hurricane - Meteorological History

Meteorological History

The cyclone was first detected in the eastern Gulf of Mexico 125 miles (200 km) west-northwest of Key West, Florida, on August 8, 1856. At the time, it was analyzed as a minimal hurricane by the Atlantic hurricane reanalysis project near Key West, but because it was already a hurricane when it was first observed, it probably had developed further east than here. It steadily advanced northwest, strengthening to the equivalent of a Category 3 hurricane. The hurricane gradually slowed prior to landfall on August 10, and it attained its estimated peak intensity of 150 mph (240 km/h). It was a tropical cyclone of small diameter, and its maximum sustained winds may have reached Category 5 status, but were unrecorded. In the early evening of August 10 the northeastern edge of the eye crossed over Last Island (Official name: Isle Dernière) before making landfall a few hours later south of New Iberia, LA. The cyclone is believed to have struck southern Louisiana at peak intensity with an approximate central pressure of 934 mbar (27.58 inHg). A ship reported a peripheral pressure of 955 mbar (28.20 inHg), so a lower pressure was based on the small size of the hurricane. It quickly weakened over land, and it diminished to a tropical storm on August 11. It dissipated over southwestern Mississippi on August 12 with fully tropical characteristics.