Hurricane Bill was a large Atlantic hurricane that brought 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 2009 Atlantic 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.
Bill caused $46.2 million in damages and two deaths over a nine-day period. As it passed close to Bermuda, the hurricane caused power outages and strong winds, though damage was minor. Despite remaining well offshore of the United States East Coast, the storm's large wind field contributed to strong surf which caused severe beach erosion. Numerous offshore rescue operations occurred as a result of people swept away by the strong waves. Both deaths caused by the hurricane were the result of drownings off the U.S. coast. In some areas of New England, the storm's outer rainbands caused flash flooding. In Atlantic Canada, Bill caused mainly power outages and flooding events. Several roads were flooded in Nova Scotia, and 32,000 people lost power. In Newfoundland, where the hurricane made landfall, strong winds caused minor tree damage. As an extratropical system, Bill dropped light rainfall in the British Isles and Scandinavia.
Meteorological history
A tropical wave moved off the western coast of Africa on August 12, 2009, and entered the Atlantic Ocean. The National Hurricane Center (NHC) remarked upon the possibility for tropical cyclone development, as the wave had already been accompanied by a broad area of shower and thunderstorm activity. The wave quickly organized, and a low pressure system formed to the south of the Cape Verde Islands on August 13. The convection became slightly less organized on August 14, though by early August 15, the NHC reported that a tropical depression was forming. The system was declared Tropical Depression Three later that day.
The newly designated depression continued to intensify, and it was quickly upgraded to Tropical Storm Bill. Numerous rainbands had begun to develop, though the storm lacked deep convection near its center. At this time, Bill was already predicted to become a hurricane. By early on August 16, the storm had developed what NHC forecasters described as a "beautiful" cloud pattern, and environmental conditions favored continued strengthening. Bill intensified to attain Category 1 hurricane status on the Saffir-Simpson Hurricane Scale early on August 17.