By July 24, Typhoon Bess began to move north-northwest and slow down due to the westward building of the subtropical ridge to the north. The JTWC expected Bess to turn west; however, Bess instead turned southwest on July 25 due to interactions with a trough. By this time, the JMA estimated winds of . Shortly thereafter, the JTWC increased the intensity of the typhoon to , equivalent to a Category 2 hurricane on the Saffir-Simpson Hurricane Wind Scale (SSHWS). After performing a small loop, the storm maintained its intensity until July 27, when the JMA raised the wind speed of Bess to . The typhoon then turned north-northwest while slowly intensifying. On July 28, the system turned northwest along the southwestern edge of the ridge. That afternoon, the JMA estimated winds of . Subsequently, Typhoon Bess entered an episode of rapid deepening. Only a few hours later, the JMA reported that Bess had attained its peak intensity of , which it would maintain for 12 hours. At 0000 UTC on July 29, according to the JMA, the typhoon attained a minimum barometric pressure of . Later that morning, the JTWC estimated that Bess attained its peak intensity of , a Category 5 hurricane-equivalent on the SSHWS, though JMA data suggests that Bess was weakening by this time. At this time, Typhoon Bess was located 460 km (285 mi) to the southeast of Iwo Jima.