Abstract:

Much of the rain that falls in monsoon regions is delivered by transient, propagating vortices that are neither typhoons nor classic extratropical baroclinic waves, but another type of synoptic-scale disturbance. This is particularly true in the South Asian monsoon, where monsoon depressions produce extreme rainfall that is responsible for the majority of that region's hydrometeorological disasters. In this presentation I present recent progress in understanding the mechanisms of genesis and amplification of monsoon depressions.  I discuss historical trends in the frequency, location, and rain rates of monsoon depressions, and present high-resolution global climate model projections of their future changes. Finally, I close by showing operational predictions of monsoon depression activity based on numerical weather prediction model output.