iselle approached hawaii as a powerful category 4 hurricane. it had sustained winds of about 120 knots (138 mph). a number of conditions caused it to weaken just before it approached hawaii. it struck the big island as a strong tropical storm. the storm center made landfall at about 2:30 am on august 8. it left downed trees and about 25,000 people without electric power. the storm surge caused 25-foot waves. airlines had to cancel about 50 flights due to the storm.