JTWC did not follow suit until early on August 18, when ship reports indicated a tighter pressure gradient and winds of . Tropical Storm Zola continued northwest and tracked through region of divergence aloft, which aided intensification. At 06:00 UTC on August 18, the JMA upgraded Zola into a severe tropical storm. Further intensification was initially halted because the storm remained embedded in the monsoon trough, but on August 19, Zola began to detach from the monsoonal trough, coinciding with an expansion of the storm's equatorial outflow channel. The cyclone subsequently resumed intensification while turning northwest in response to a subtropical ridge between China and Japan. Following the appearance of a ragged eye on weather satellite imagery and a Dvorak classification of T4.0/, Zola was classified as a typhoon at 00:00 UTC on August 20 by the JTWC. The JMA followed suit later that same morning. Further intensification was aided by a tropical upper tropospheric trough that provided an excellent poleward outflow channel. Based an increase in the storm's organization, the JTWC raised the intensity of the storm to at 06:00 UTC on August 21, its peak intensity. Around this time, the JMA estimated that Zola peaked in intensity, with winds of and a minimum barometric pressure of . Increased southwesterly wind shear took toll on the typhoon, and the storm weakened slightly prior as it passed between Kyushu and Shikoku, with the JTWC and JMA reporting winds of respectively at the time of landfall on western Honshu. After recurving to the northeast over the Sea of Japan, Zola weakened to a tropical storm on August 22 and transitioned into a mid-latitude cyclone while interacting with the westerlies early on August 23. Both agencies ceased tracking the system at this time. Impact The typhoon dropped heavy rainfall across much of the Japanese archipelago. A peak rainfall total occurred of at Yanase Station. A peak hourly rainfall total of was observed in Miyagawa. Meanwhile, a peak daily precipitation total of fell in Motoyama. A wind gust of was recorded on Muroto. Near where the storm moved over Shikoku island, in Kōchi Prefecture, three people suffered injuries. Three homes were destroyed, with an additional thirty-five harmed. Roads were damaged in 368 locations. Throughout the prefecture, damage totaled ¥5.29 billion (US$36.7 million). Roads were harmed in one hundred twenty-seven locations while bridges sustained damage in four locations in Tokushima Prefecture. Across Kagawa Prefecture,