Hurricane Bill was a relatively large Atlantic tropical cyclone, attaining a maximum gale-diameter of 460 mi (740 km). A Cape Verde type hurricane, Bill originated from a tropical wave that emerged from the western coast of Africa on August 12, and organized into a tropical depression near the Cape Verde islands on August 15. The depression was quickly upgraded to a tropical storm, earning the name Bill. Tracking generally west-northwestward, the tropical system attained hurricane status on August 17 and major hurricane status on August 18. The following day, Bill attained peak intensity with winds of 135 mph (217 km/h) and a minimum central pressure of 943 mbar (27.8 inHg). It weakened as it veered north, passing Bermuda with little impact, and Bill lost tropical characteristics as it passed over Nova Scotia and Newfoundland. However, waves up the East Coast killed two people, and the hurricane passed close enough to warrant tropical cyclone watches and warnings in both the United States and Canada.
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.
By late August 17, satellite imagery indicated that an eye feature may have been developing. Bill sustained deep convection and well-established upper-level outflow; it was upgraded to Category 2 status shortly before undergoing an eyewall replacement cycle. Early August 18, the storm had established a very symmetric and well-organized appearance on satellite imagery, and a large, pronounced eye. The storm was moving west-northwestward under the steering currents of a subtropical ridge to the north. Information derived from Hurricane Hunter reports and satellite imagery indicated that the storm had strengthened and reached Category 3 intensity on August 18, making it a major hurricane. Despite some wind shear, Bill was upgraded further to Category 4 intensity on August 19 and reached maximum size with hurricane force winds extending 115 miles (180 kilometers) and tropical storm force winds extending 290 miles (467 kilometers) from the center
On August 20, the storm began to weaken, being downgraded to a Category 3, as convection associated with it diminished somewhat. The storm's eyewall also weakened, with a portion of it dissipating later that day. Shear also deteriorated the structure of the storm, with clouds being displaced from the main circulation. However, shortly after, the eye became much better defined and developed several mesovortices, a feature typical of intense hurricanes. On August 21, Bill was downgraded to a Category 2 hurricane as the structure of the storm deteriorated; however, the atmospheric pressure in the eye was 954 mbar (hPa) at that time, equivalent to a strong Category 3 storm. By the morning of August 22, the hurricane completed an eyewall replacement cycle and featured a 55 mi (88 km) wide eye.
Later on August 22, the storm weakened to a Category 1 hurricane as Bill tracked over cooler waters. The storm maintained its intensity through August 23 as it retained its cloud-filled eye and tracked at a quick pace to the north-northeast producing 26.4 m (87 ft) waves at La Have Bank Buoy (station 44142) (Lat: 42.50N, Lon: 64.02W) and 16 ft surge on coastlines in New England and Nova Scotia. The storm then made landfall shortly before midnight local time, at Point Rosie, on the Burin Peninsula of Newfoundland as a marginal Category 1 hurricane. Shortly after this it was downgraded to a tropical storm, and then lost tropical characteristics. The remnants of Bill crossed the Atlantic Ocean as an extratropical storm and later impacted the United Kingdom with heavy rain and surf.
On August 18, the Emergency Measures Organisation (EMO) of Bermuda advised the public to begin preparing for Hurricane Bill. Derrick Binns, Permanent Secretary of the Ministry of Labour, Home Affairs and Housing, reported that "We have been following the storm closely since its inception, and today we reviewed our planning and procedures to ensure all are in sync. While we have not as yet issued hurricane warnings, I think it is important to advise residents to check their emergency kits to be sure supplies are adequate." Residents on the island were instructed to review their emergency supplies, while boat owners were urged to secure their watercrafts. By August 20, preparations had expanded as the projected path of Bill was to pass 200 miles west-southwest of the British overseas territory early on August 22. Late on August 21, The Causeway bridge linking the eastern parish of St. Georges was closed as well as L.F. Wade International Airport. Ferry service was cancelled until August 23. Late on August 21, tropical storm force winds were observed in Bermuda with some gusts above hurricane force.
In response to predictions of rough surf and rip currents, the Atlantic Beach, North Carolina fire department planned to increase the number of on-duty lifeguards. On Long Island, New York, local officials began tracking Hurricane Bill and initiating preparations. Local crew workers trimmed trees to reduce the amount of airborne debris. On August 17, the United States Army assessed 30 key buildings for power needs. Residents were urged to stock up on food and emergency supplies as officials estimated that in the event of a hurricane emergency, nearly 650,000 people would not have access to shelter. The Suffolk County Red Cross began organizing catering agencies to prepare meals to supply shelters. The Long Island Power Authority also took preventative measures. On August 20, the Massachusetts Emergency Management Agency made several conference calls with the National Weather Service about possible impacts from the storm in the state, particularly in Cape Cod. Bill came close enough to the region to warrant a tropical storm warning for a while.
Peter Bowyer, Program Supervisor of the Canadian Hurricane Centre, advised Nova Scotia residents to monitor the storm's progress and take necessary precautions. He said it is "almost inevitable that the storm will find some part of Eastern Canada. Whether that’s the marine areas or the land district, it's still too far to say." Dozens of flights were canceled ahead of the storm at Halifax Stanfield International Airport and ferry service between Nova Scotia and Newfoundland was temporarily canceled. Offshore, the Exxon Mobil corporation evacuated nearly 200 personnel from a project near Nova Scotia as a precaution. On August 22, officials announced that all parks in Nova Scotia would be closed for the duration of Hurricane Bill.
On August 22, Environment Canada, the meteorological agency of Canada, issued a tropical storm warning from Charlesville in Shelburne County, Nova Scotia eastward to Ecum Secum in the Halifax Regional Municipality. A hurricane watch was issued for areas between Ecum Secum eastward to Point Aconi. The remaining north coast of Nova Scotia, Prince Edward Island and western Newfoundland were placed under a tropical storm watch. Several hours later, the tropical storm warning was extended to include the areas under a hurricane watch and most of Newfoundland was placed under a tropical storm watch. Early on August 23, a tropical storm warning was issued in Newfoundland for areas between Stone's Cove and Cape Bonavista. About 150 people were evacuated from two senior homes in Newfoundland and the town of Placentia was put under a state of emergency in fears of storm surge damage.
Republic of Ireland and United Kingdom
On August 25, Met Éireann issued gale warnings across the south of Ireland, and advised small boats not to go out to sea until the system had passed. They also forecast up to 1 in (25 mm) of rain across Ireland. The Met Office in the UK issued severe weather warnings in preparation for the arrival of the storm.
On August 19, Peter Bray, a British rower attempting to break the record for the quickest solo crossing of the Atlantic was forced to abandon his boat and board the RRS James Cook due to being in the path of Hurricane Bill. Large, life-threatening swells produced by the storm impacted north-facing coastlines of Puerto Rico and Hispaniola as Hurricane Bill approached Bermuda.
In Massachusetts, outer bands of Hurricane Bill produced significant amounts of rainfall, peaking at 3.74 in (95 mm) in Kingston, Massachusetts. Most areas along the eastern portion of the state received rain during the night of August 22 into the morning of August 23, with several areas exceeding 2 in (51 mm). On Long Island, beach damage was severe; in some areas the damage was the worst since Hurricane Gloria in 1985. Along the coasts of North Carolina, waves averaging 10 ft (3.0 m) in height impacted beaches. In Wrightsville Beach, up to 30 rescues were made due to strong rip currents and large swells; however, only one incident resulted in hospitalization. Severe beach erosion took place at Bald Head Island, where 150 ft (46 m) of beach was washed away, resulting in the loss of the remaining sea turtle nests.
Along the coastlines of Virginia, Maryland, and Delaware, waves were estimated to have reached 8 ft (2.4 m) at the height of the event. Beaches along the Georgia coastline, located nearly 600 mi (970 km) from Bill, recorded large swells from the storm and strong rip currents. In Delaware, waves peaked near 10 ft (3.0 m), resulting in one serious injury after a man was tossed by a wave and thrown face-first into the sand.Waves along the Georgia coast averaged 5 to 6 ft (1.5 to 1.8 m) in height with some reaching 8 ft (2.4 m). This resulted in numerous lifeguard rescues and some minor coastal flooding. Beaches along Long Island were closed after waves up to 12 ft (3.7 m) began to cause coastal flooding and beach erosion. All beaches around New York City were closed due to the risk of strong rip currents and waves up to 20 ft (6.1 m). In southern New York, a cold front stalled by Hurricane Bill produced torrential rainfall, amounting to at least 2 in (51 mm) in a few hours, causing flash flooding and a tornado in Maine. Lightning produced by severe thunderstorms also left 5,000 residences without power.
In New York, severe beach erosion caused by the storm resulted in over $35.5 million in losses.
A 7-year-old girl drowned after she, her father, and a 12-year-old girl were swept off a rocky ledge near Acadia National Park in Maine on August 23. The three were part of an early afternoon crowd of thousands who lined the Maine's national park's rocky shoreline to watch the high surf and crashing waves. Authorities said that about 20 people were swept away, but 17 of them made back to shore safely. Eleven were sent to area hospitals for spinal cord injuries.
A 54 year old man drowned at New Smyrna Beach, Volusia County, Florida due to the heavy surf.
Two lifeguards at Mecox Beach in Watermill, New York accompanied endurance artist David Blaine back to shore after he was allegedly caught in a rip current after ignoring signs and verbal warnings not to swim in the ocean on August 23. Blaine said he was not in trouble and did not need the rescue.
Several buildings were damaged or destroyed on Mount Desert Rock (MDR), a 3-acre island off the coast of Mount Desert Island, Maine. The island, once a manned lighthouse station, now serves as a marine mammal research platform for the research group Allied Whale, based out of College of the Atlantic in Bar Harbor. The lighthouse, still operated by the Coast Guard, was relatively untouched by the wave energy of the hurricane. However, the waves did take out all but one wall of the historic boathouse, three walls of a two-story generator shed, and destroyed most of the first floor of the lighthouse keepers house. College of the Atlantic is in the process of rebuilding these historic stuctures, and continue to conduct research on the island.
Further inland, a band of heavy rain fueled by tropical moisture from Bill produced upwards of 5 in (130 mm) in southern New Hampshire during an eight hour span. The intense rainfall led to significant flash flooding that covered several roads and inundated homes. Mudslides also closed roads in portions of the state as hillsides collapsed. Seven people required water rescue after their cars stalled in floodwaters. Overall, the floods left roughly $700,000 in damages in New Hampshire but no fatalities or injuries.
Bermuda and Canada
The hurricane had little impact in Bermuda. A public high school was designated as an emergency shelter, into which The Salvation Army took six homeless people. Some 3,700 households experienced power outages at some point during the storm, and in some instances cable television and internet services were also interrupted, particularly in the central Spanish Point headland. During the daytime on Saturday, public works crews performed cleanup of light debris, mostly discarded garbage unveiled by the storm.
Throughout the British Isles, the remnants of Bill produced high winds and heavy rains. All of Ireland and most of the United Kingdom was affected by the storm in some way. Rainfall in the United Kingdom peaked at 31 mm (1.2 in) in Shap. After passing through the British Isles, the remnant system affected parts of Scandinavia before dissipating.