Hurricane Hanna

Hurricane Hanna

Category 1 hurricane (SSHWS/NWS)
Hurricane Hanna at peak intensity over the Turks and Caicos Islands on September 1
Formed	August 28, 2008
Dissipated	September 7, 2008
Highest winds	1-minute sustained: 85 mph (140 km/h)
Lowest pressure	977 mbar (hPa); 28.85 inHg
Fatalities	≥532 direct, 5 indirect
Damage	$160 million (2008 USD)
Areas affected	Puerto Rico, Turks and Caicos Islands, Bahamas, Hispaniola, Eastern Seaboard, Atlantic Canada
Part of the 2008 Atlantic hurricane season

Hurricane Hanna was the deadliest storm of the 2008 Atlantic hurricane season. The storm was the eighth tropical cyclone and fourth hurricane of the 2008 Atlantic hurricane season. It formed east-northeast of the northern Leeward Islands on August 28. The cyclone struck Myrtle Beach, South Carolina, before moving up the Eastern Seaboard to become an extratropical cyclone as it moved by New England into Atlantic Canada early on September 7. The system raced across the North Atlantic, sweeping west of Great Britain on September 10 before turning north and becoming absorbed by a stronger extratropical cyclone between Iceland and Greenland late on September 12. At least 537 deaths were reported (the final death toll will likely never be known), mostly due to flooding in the northern part of Haiti, making it the deadliest tropical cyclone in the Atlantic basin since Hurricane Stan in 2005. Hanna also caused $160 million in damages to the U.S, but the exact damage in Haiti is unknown.

During late August 2008, a tropical wave emerged off the coast of Africa and tracked westward across the Atlantic Ocean. After several days, an associated area of low pressure gained deep convection and organization. On August 28, while to the east-northeast of the northern Leeward Islands, the low formed into Tropical Depression Eight. Later that day, it attained tropical storm status, and as such was named Hanna by the National Hurricane Center. At the time, the low-level center of circulation was partially exposed on the western edge of the convection, indicating westerly wind shear.

Tracking westward primarily under the steering current of a large ridge to the north, the convective pattern began to redevelop late on August 28. Since forecast, models predicted the storm would weaken and move southwestward due to outflow associated with nearby Hurricane Gustav. Despite this, the storm began entering a favorable environment, and was forecast to intensify. An upper-level low that had been producing wind shear moved away from the system, though light shear continued. At the same time, the low-level center once again became separated from the convection, which was primarily confined to a cyclonic banding feature in the eastern half of the circulation. It remained weak as it moved erratically westward while east of the Bahamas on August 30. Due to the influence of Hurricane Gustav's large circulation, Hanna suddenly took a sharp southerly turn and slowed down to drift while located to the north of the Turks and Caicos Islands. On September 1, as Hanna drifted to the south-southwest, convection increased and the storm began to intensify. Later that day around 1:30 pm EDT, an Air Force Reconnaissance Aircraft found winds within Hanna supportive of hurricane strength, and the National Hurricane Center upgraded Hanna to a hurricane. Early on September 2, strong wind shear in association with Hurricane Gustav began to affect Hanna and the storm was downgraded to a tropical storm on September 3. Hanna then sharply turned back northward, causing additional damage in Haiti. Over the course of the next three days, Hanna slighted northwestward towards the Bahamas, before turning abruptly north. By September 5th, Hanna turned westward towards the Carolinas. Early on September 6, 2008, Hanna made landfall near the South Carolina-North Carolina border. The system became an extratropical cyclone as it moved into Atlantic Canada early on September 7 and raced across the North Atlantic, sweeping west of Great Britain on September 10 before turning north and becoming absorbed by a stronger extratropical cyclone between Iceland and Greenland late on September 12.