Widespread thunderstorm activity over northwest India on 26 May 1986- Satellite and synoptic studies

Abstract

The growth and evolution of a persistent mesoscale convective complex have been depicted by INSAT cloud imagery. Using satellite cloud imagery and conventional data, it is possible to identify the area of severe convective activity well in advance, New area of imminent development can be predicted from cloud top temperature contours prepared from infrared cloud imagery, Synoptic, dynamic and thermodynamic analysis have revealed that low-Level convergence, presence of small scale low-level vortex, moisture incursion to the disturbed area, strong surface heating, temperature and moisture contrast, below normal upper air temperature and above normal upper air vertical wind shear are responsible for this development. Persistence may be due to hydro dynamical effect of the environmental flow around the cloud mass and cyclonic flow embedded in it. Upper air divergence field may not be a necessary condition for formation of convective complex.