 After maintaining Category 4 status on the Saffir-Simpson Hurricane Scale for about 18 hours, southwesterly wind shear slightly disrupted the inner core of the hurricane, and Ioke quickly weakened to winds of about .Late on August 22, the hurricane passed about south of Johnston Atoll, with the northeastern portion of the eyewall crossing the atoll early on August 23.After turning westward later in the day, wind shear began to decrease, allowing a second period of rapid deepening.