High Quality Content by WIKIPEDIA articles! The effects of Hurricane Isabel in Maryland and Washington, D.C., were among the most damaging from a tropical cyclone in the Baltimore-Washington Metropolitan Area, United States. 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.