 After entering the Gulf of California, an eye began to become apparent on visible satellite imagery, and it is estimated Isis attained hurricane status late on September 2.Continuing northward, it struck Topolobampo in the state of Sinaloa early on September 3 as a minimal hurricane.Isis weakened to a tropical storm a few hours after landfall, and subsequent to turning to the north-northwest the low-level circulation dissipated over Sierra Madre Occidental.