After becoming a hurricane, Gordon underwent rapid deepening as the eye became better defined and more intense. In 24 hours, the winds increased by to a peak intensity of early on September 14, while located about southeast of Bermuda. This made Gordon a major hurricane, specifically a Category 3 on the Saffir-Simpson scale, the first of 2006. As it curved to the northeast, the hurricane maintained its peak intensity for about 24 hours, during which the eye decreased in size and the eyewall convection weakened. Afterward, Gordon began weakening due to moving over an area of cooler water temperatures. On September 15, the trough that was previously guiding the hurricane moved farther away, allowing the ridge to build to the north and causing Gordon's motion to become nearly stationary. Increased wind shear imparted further weakening, and the hurricane's slow motion resulted in upwellingthe motion of cooler water to the ocean's surface. On September 17, a building ridge to the east caused Gordon to begin a steady northeast motion. By that time, the convection had diminished significantly and the winds weakened to minimal hurricane-force. One NHC forecast predicted extratropical transition to occur within 48 hours.