In late April, the Intertropical Convergence Zone became very active over the Bay of Bengal and later spawned a low-pressure area on April 26. Accompanied by low wind shear, favorable outflow, and over an area of high sea surface temperatures, the system consolidated into a depression the following day. Tracking slowly westward, the depression intensified, becoming Cyclonic Storm Nargis on April 28. That day, steering currents weakened, causing the system to become nearly stationary before a trough influenced more northeasterly, and later easterly, movement. On April 29, the system attained hurricane-force winds. Hours before striking southern Myanmar on May 2, Nargis attained its peak intensity with winds of 165 km/h (105 mph) and an estimated central pressure of 962 mbar (hPa; 28.41 inHg). The JTWC estimated the system to have been somewhat stronger, attaining one-minute sustained winds of 215 km/h (135 mph). Once onshore, the system gradually weakened and dissipated early on May 4.