Eye of hurricane Isabel. This image was taken from the International Space Station on 15th September 2003. At this time, the hurricane had not made landfall, and was classed as category 5, the strongest type of hurricane. At this stage, the winds were gusting at over 250 kilometres per hour. Hurricanes are enormous rotating storm systems that typically form in late summer. They are powered by evaporation from a warm sea surface, and weaken as they pass over land. Hurricane Isabel is one of the largest and most powerful hurricanes of recent years. It hit the east coast of the USA on 18th September 2003.