 The effects of Hurricane Isabel on North Carolina were the worst from a hurricane since Hurricane Floyd made landfall in 1999 . 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 165 mph ( 265 km / h ) 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 105 mph ( 165 km / h ) on September 18 . It quickly weakened over land and became extratropical over western Pennsylvania the next day . 
