Category 4 major hurricane (SSHWS/NWS) | |
Hurricane Bill as a Category 4 hurricane on August 19
|
|
Formed | August 15, 2009 |
---|---|
Dissipated | August 26, 2009 |
(Extratropical after August 24) | |
Highest winds |
1-minute sustained: 130 mph (215 km/h) |
Lowest pressure | 943 mbar (hPa); 27.85 inHg |
Fatalities | 2 direct |
Damage | $46.2 million (2009 USD) |
Areas affected | Northeastern Caribbean, United States East Coast, Bermuda, Atlantic Canada, Europe |
Part of the 2009 Atlantic hurricane season |
Hurricane Bill was a large Atlantic tropical cyclone that wrought minor damage across mainly Atlantic Canada and the East Coast of the United States during August 2009. The second named storm, first hurricane, and first major hurricane of the annual hurricane season, Bill originated from a tropical wave in the eastern Atlantic on August 15. Initially a tropical depression, the cyclone intensified within a favorable atmospheric environment, becoming Tropical Storm Bill six hours after formation. Steered west-northwest around the southern periphery of a subtropical ridge to the northeast of the cyclone, Bill passed through the central Atlantic. At 0600 UTC on August 17, the cyclone strengthened into a Category 1 hurricane on the Saffir–Simpson hurricane wind scale; within 36 hours, Bill entered a period of rapid deepening and intensified into a major hurricane with winds of 115 mph (185 km/h). Passing well northeast of the Lesser Antilles, Bill attained its peak intensity with maximum sustained winds of 130 mph (215 km/h) and a minimum barometric pressure of 943 mb (hPa; 27.85 inHg) on August 19 and August 20, respectively. Thereafter, an approaching trough induced higher vertical wind shear across the region, causing slow weakening of the hurricane; this same trough resulted in an accelerated motion and curve northward. As the storm passed Bermuda, it contained sustained winds equal to a Category 2, and ultimately struck Newfoundland as a tropical storm. After moving inland and weakening to a tropical storm, Bill began an extratropical transition; this alteration in structure was completed by 1200 UTC on August 24. Two days later, Bill's remnant low was absorbed into a larger extratropical system over the Northern Atlantic.