Out of the five equatorial vortices studied in this investigation, the following significant features are obtained. 1. Disturbances in the trades associated with lateral shear were found to be important for the genesis of these equatorial vortices. 2. Intensification of these disturbances depended very much on the timing of the occurrence of the cold surge and the presence of the disturbance in the trades. 3. Low-Ievel easterly jets at 850 mb were found over the northem part of Peninsular Malaysia during the intensification stage of the four equatorial vortices that interacted with the cold...