From its genesis, the storm moved northwestward, being gradually strengthened, amplified by a wind surge from the south. By 26 April, wind shear had decreased to near zero as an anticyclone developed aloft the hurricane. Around this time, the cyclone rounded the western periphery of a large subtropical ridge over Thailand, and the storm turned northward between the ridge to the northeast and northwest. On 28 April, the flow of the southwesterlies caused the cyclone to accelerate to the north-northeast. This flow also amplified the storm's outflow, and the cyclone intensified further. By 12:00 UTC on 28 April, or about 31 hours before landfall, the JTWC was correctly forecasting a landfall in southeastern Bangladesh. Early on 29 April, the IMD upgraded the system to a super cyclonic storm - the highest category - and estimated peak winds of 240 km/h (150 mph). The JTWC estimated peak winds of 160 mph (260 km/h), the equivalent to a Category 5 hurricane on the Saffir-Simpson scale or a super typhoon. The cyclone's high winds and low pressure, a rarity for the Bay of Bengal, ranked it among the most intense cyclones in the basin. At 19:00 UTC on 29 April, the cyclone made landfall about 55 km (35 mi) south of Chittagong in southeastern Bangladesh while slightly below its peak strength. Moving through the mountainous terrain of the Chittagong Hill Tracts, the cyclone quickly weakened and crossed into northeast India, where it degenerated into a remnant low-pressure area.