Elevation-dependent characteristics of widespread rainfall extremes along the Western Ghats

Deciphering the rainfall trends over the Western Ghats situated along the west coast of India has been the subject of several recent studies. However, less attention is rendered, particularly to understanding the spatial characteristics of atmospheric features associated with widespread and elevation-dependent extreme rainfall occurrences over this region and this study intends to provide some insights into this aspect. This study observes a rising trend in extreme rainfall events over the Western Ghats during the 1979–2020 period, consistent with earlier investigations. The extreme rainfall events on the windward side located below and above 500 m above sea level exhibit different background circulation signatures, such as mean wind speeds of low-level jets and moist static stability. The extreme rainfall events seen below [above] 500 m above sea level occur in the backdrop of mesoscale [large-scale] monsoon circulation. A Froude number analysis further elucidates the importance of Western Ghats foothill topography in complementing the development and spatial segregation of extreme rainfall occurrences.