By September 4, 2011, Katia had strengthened to a Category 2 hurricane. At 11:00 a.m. Atlantic Standard Time (AST) on September 4, the U.S. National Hurricane Center (NHC) reported that Katia had winds of 100 miles (160 kilometers) per hour with higher gusts.
The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this natural-color image at 10:45 a.m. AST on September 4. Katia sports the spiral shape and distinct eye characteristic of strong storms. This image captures Katia north of the Leeward Islands and northeast of Puerto Rico.
The NHC reported that Katia had strengthened rapidly to a Category 2 hurricane by September 4. The storm was expected to continue intensifying over the next couple days as Katia traveled toward the northwest.