High Quality Content by WIKIPEDIA articles! Hurricane Katia was the eleventh named storm, second hurricane and second major hurricane of the 2011 Atlantic hurricane season. A Cape Verde-type hurricane, Katia developed from a tropical wave south of the Cape Verde Islands on August 29. Tracking west-northwestward, the system gradually strengthened within an area supportive of tropical development. Late on August 31, Katia was estimated to have attained hurricane status well away from land. In the morning of September 4, it strengthened rapidly to reach Category 2 status. During the course of the day on September 5, it grew in strength to become a Category 4 hurricane. On September 6, it weakened steadily to a Category 1 hurricane, and four days later it became extratropical, while located to the south of Newfoundland. The extratropical system then moved east-northeast towards the United Kingdom, and made landfall there with winds near 70 mph (110 km/h). Katia`s remnant merged with a larger extratropical system, at 0000 UTC on September 13, over the North Sea.