Wind characteristics of the troposphere and lower stratosphere during the passage of a tropical cyclone over India using VHF radar

A tropical depression formed in the west central Bay of Bengal on 15th October 2001 intensified into a cyclonic storm and crossed over the Indian mesosphere–stratosphere–troposphere (MST) Radar site at Gadanki (13.5°N, 79.2°E), India on the next day morning. Three-dimensional wind characteristics of the troposphere and lower stratosphere have been studied based on the continuous observations using MST radar at Gadanki during 15–16 October 2001. Horizontal wind components in the upper troposphere and lower stratosphere showed an abrupt increase during the passage of the storm, whereas the wind changed its direction and became very weak in lower levels (4–8 km). The observed vertical velocity was very high in the level of maximum convective outflow (10–12 km). After the passage of the cyclonic storm upper and lower tropospheric wind speed reduced considerably, whereas the mid-tropospheric wind speed increased.