Role of east-west shear zone and wind confluence on the occurrence of intense heavy rainfall over North Konkan during southwest monsoon season

Abstract

An attempt has been made to understand the mechanism in occurrence of intense heavy rainfall events over North Konkan and adjoining areas using observed, satellite and reanalysis datasets. Synoptic conditions associated with Dahanu heavy rainfall event, 2016, Mumbai floods, 2005 and historical heavy rainfall events over North Konkan region are considered in the present study. In presence of East-West shear zone with upper air cyclonic circulations extending up to mid-tropospheric levels located at west central Bay of Bengal, west Arabian Sea and anti-cyclonic circulation over east-central Arabian Sea were the major synoptic features observed during these events. Results suggest that the confluence of moisture-laden winds from these circulations over North Konkan lead to the occurrence of intense heavy rainfall events.