Boundary layer signatures of consecutive thunderstorms as observed by Doppler sodar over western India

Thunderstorm development in terms of turbulence and wind fields observed using Doppler sodar (June 4–6, 2009) is presented. Vertical velocity averaged over convective hours shows net updrafts prior to thunderstorm in contrast to net downdrafts on a normal day (June 4). Moisture availability due to thundershower on June 5 helps develop another thunderstorm on June 6 even with reduced temperature and turbulent kinetic energy. Two thundershowers on June 6 at a time interval of 4 h are observed to have different triggering mechanisms; viz. convective overturning and forced uplifting of stable moist air mass by flow convergence. Shear in wind speed and/or direction prior to thunderstorm and accelerating outflow following the precipitation are the common features observed.

Research HighlightsABL signatures of thunderstorm (TS) evolution by Doppler Sodar derived 3D wind fields. ► Net updrafts observed in CBL on TS day in contrast to net downdrafts on no-TS day. ► Precipitation induced moisture aids TS to develop under lesser temperature and TKE conditions. ► TS, hours apart, triggered by convective overturning and forced moisture convergence.