Extratropical cyclone (SSHS) | |
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Extratropical remnant of Isabel | |
Areas affected | Canada |
Date | September 19, 2003 |
Highest winds |
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Fatalities | 1 indirect |
Damage | Unknown |
Part of the 2003 Atlantic hurricane season | |
Part of a series on Hurricane Isabel | |
Effects
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The effects of Hurricane Isabel in Canada were fairly minor due to Isabel transitioning into an extratropical cyclone before affecting the area. Hurricane Isabel formed from a tropical wave on September 6, 2003 in the tropical Atlantic Ocean. It moved northwestward, and within an environment of light wind shear and warm waters it steadily strengthened to reach peak winds of 265 km/h (165 mph) on September 11. After fluctuating in intensity for four days, Isabel gradually weakened and made landfall on the Outer Banks of North Carolina with winds of 165 km/h (105 mph) on September 18. It quickly weakened over land and became extratropical over western Pennsylvania the next day before entering southern Ontario.
Impact from the storm was fairly minor, including downed trees and power lines across southern Ontario. Isabel was indirectly responsible for one traffic fatality. A group of researchers flew into Isabel over Lake Erie and southern Ontario to study tropical cyclones transitioning into extratropical cyclones. The group also flew into two previous cyclones affecting Canada.
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Before moving into the country, Isabel was consistently forecast to enter Canada as an extratropical cyclone.[1] On September 18, the Canadian Hurricane Centre issued heavy rainfall and wind warnings for portions of southern Ontario. A gale warning was also issued for Lake Ontario and the eastern region of Lake Erie.[2] Subsequently, officials issued a gale warning for the Saint Lawrence River[3] and Georgian Bay, and also extended the heavy rainfall warning to portions of northern Ontario.[4] Most warnings were canceled when the extratropical remnant weakened further.[5] A news report on September 14 warned conditions were probable for a repeat of the disaster caused by Hurricane Hazel 49 years prior, resulting in widespread media coverage on the hurricane.[6]
A group of Canadian researchers organized a Convair 580 flight out of Ottawa to fly into Isabel to study the structure of a storm transitioning into an extratropical cyclone by collecting data from radar and dropsondes. The plane flew generally south of the center, and while passing through the area of heaviest precipitation, ice accumulated up to 25 mm (1 inch) thick, forcing the pilot to descend. The flight was the first Convair flight into a storm undergoing extratropical transition over land, though was similar to the two previous flights over water for Hurricane Michael in 2000 and Tropical Storm Karen in 2001.[7]
Swells from Isabel produced moderate surf conditions along the Atlantic coast of Nova Scotia, particularly in the Gulf of Maine. No direct observations were recorded, though swells of 2 to 3 m (6 to 10 feet) were expected.[2] Isabel produced rough surf in Lake Ontario while passing the lake, with waves reaching 4 m (13 ft) along the western portion of the lake. At Hamilton, the waves surpassed seawalls and produced spray onto coastal streets.[7] Rainfall first began affecting Ontario early on September 19 as the diminishing rainbands moved over the southern portion of the province. Precipitation reached 53.4 mm (2.1 inches) at Point Pelee,[3][5] with 33.2 mm (1.3 inches) reported at Toronto Pearson International Airport.[8] Most of the rainfall fell near and west of the storm's track,[7] causing localized flooding.[6]
The strong pressure gradient between Isabel and a high pressure system over eastern Canada produced strong easterly winds across Lakes Ontario and Erie.[7] A buoy in Lake Ontario reported a peak gust of 78 km/h (49 mph).[8] On land, gusts of 73 km/h (45 mph) occurred in numerous locations,[6] with Port Colborne reporting a peak gust of 81 km/h (51 mph).[1] The winds downed trees across southwestern Ontario, causing power outages after they fell onto power lines.[7] One person died in a traffic fatality in Ontario as a result of the storm.[9]
Power workers throughout Canada assisted the severely affected power companies from Maryland to North Carolina.[10] Hydro-Québec sent 25 teams to the New York City area to assist in power outages.[11]
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