a strong Category 4 hurricane. A weakness in the ridge to its north allowed the hurricane to turn to the west-northwest. After completing the replacement cycle, the hurricane's large 40 mile (65 km) wide eye became better defined, and late on September 13, Isabel re-attained Category 5 status. During this time, Isabel attained annular characteristics, becoming highly symmetrical in shape and sporting a wide eye. Hurricane Isabel also displayed a "pinwheel" eye, a rare feature that is found in some annular tropical cyclones. A NOAA Hurricane Hunter Reconnaissance Aircraft flying into the hurricane launched a dropsonde which measured an instantaneous wind speed of , the strongest instantaneous wind speed recorded in an Atlantic hurricane. Cloud tops warmed again shortly thereafter, and Isabel weakened to a strong Category 4 hurricane early on September 14. Later that day, it re-organized, and for the third time, Isabel attained Category 5 status while located 400 miles (650 km) north of San Juan, Puerto Rico. Cloud tops around the center warmed again early on September 15, and Isabel weakened to a Category 4 hurricane. Later that day, the inner core of deep convection began to deteriorate, while the eye decayed in appearance. As a ridge to its northwest built southeastward, it resulted in Isabel decelerating as it turned to the north-northwest. Increasing vertical wind shear contributed in weakening the hurricane further, and Isabel weakened to a Category 2 hurricane on September 16, while located 645 miles (1035 km) southeast of Cape Hatteras, North Carolina. Convection remained minimal, though outflow retained excellent organization, and Isabel remained a Category 2 hurricane for two days, until it made landfall between Cape Lookout and Ocracoke Island on September 18, with winds of 105 mph (165 km/h). Isabel was a large hurricane at landfall, with a windfield of 460 miles (740 kilometres). The system weakened after it made landfall, though due to its fast forward motion, Isabel remained a hurricane until it reached western Virginia, early on September 19. After passing through West Virginia as a tropical storm, Isabel became extratropical over Western Pennsylvania, near Pittsburgh. The system continued turned northward, and crossed Lake Erie into Canada. Early on September 20, the extratropical remnant of Isabel was absorbed by a larger extratropical storm, over the Cochrane District of Ontario. Preparations Two days before Isabel made landfall, the National Hurricane Center issued a hurricane watch from Little River, South Carolina to