Hurricane Katia was a classic Cape Verde hurricane that caused substantial impact across Europe as a post-tropical cyclone. The eleventh named storm, second hurricane, and second major hurricane of the active 2011 Atlantic hurricane season, Katia originated as a tropical depression from a tropical wave over the eastern Atlantic on August 29. It intensified into a tropical storm the following day and further developed into a hurricane by September 1, although unfavorable atmospheric conditions hindered strengthening thereafter. As the storm began to recurve over the western Atlantic, a more hospitable regime allowed Katia to become a major hurricane by September 5 and peak as a Category 4 hurricane with winds of 140 mph (220 km/h) that afternoon. Internal core processes, increased wind shea