Two‐day disturbances in the equatorial western Pacific

From November 1992 to February 1993, westward‐propagating disturbances with scales of 1000‐1500 km frequented the equatorial western Pacific. They propagated at about 16 m s −1 and thier passage was accompanied by a two‐day oscillation in high cloudiness. Their convection was most intense when the lower troposphere was cool and the level of free convection was relatively low. The disturbances propagated westward at about 18 m s −1 faster than the lower tropospheric flow. This rapid propagation may have been the result of a coupling between the disturbance's convection and the 20 m s −1 vertical mode. The signal of this mode was apparent in vertical profiles of temperature and wind and the most intense convection began when the mode dynamically cooled the lower troposphere, lowering the level of free convection.