 The effects of Hurricane Isabel in Delaware resulted in one of only thirteen presidential disaster declarations for the state of Delaware . 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 Pennsylvania the next day . The storm 's center remained to the south and west of Delaware , and was about 175 miles ( 280 km ) from Delaware at its closest approach . At that time , Isabel was a strong tropical storm located in central Virginia . 
