Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Hurricane Katia was the eleventh named storm, second hurricane and second major hurricane of the 2011 Atlantic hurricane season. Katia developed as a classical long-lived Cape Verde-type hurricane 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. On September 1, Katia was downgraded to a tropical storm after wind speeds dropped below hurricane strength. The following day, it was upgraded back to a Category 1 hurricane, then back down to a tropical storm on September 3. 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.