Typhoon Ivan, known in the Philippines as Typhoon Narsing, was an intense tropical cyclone that existed simultaneously with another storm of the same intensity, Typhoon Joan, in October 1997. Forming out of an area of disturbed weather on October 13, Ivan gradually intensified into a typhoon as it tracked steadily to the west-northwest. On October 15, the storm underwent rapid intensification and reached an intensity corresponding to Category 5 status on the Saffir–Simpson Hurricane Scale. Late on October 17, Ivan reached its peak strength with winds of 295 km/h (185 mph) and a barometric pressure of 905 hPa (mbar). Shortly thereafter, the typhoon began to weaken as it approached the Philippines. Ivan eventually made landfall in northern Luzon with winds of 220 km/h (140 mph) on October 20