In certain years, during the onset of the Indian Summer Monsoon, a synoptic scale vortex, known as the Monsoon onset vortex (MOV) forms in the Arabian Sea within the seasonal northward propagating region of precipitating convection. Many MOVs intensify into tropical cyclones and significantly impact the onset and advance of the Monsoon. This work focuses on the case studies of past MOVs and the associated monsoon features in the UFS S2S prototypes 5, 6, and 8. The UFS performance varies for the 3 MOV cases of 2011, 2014, and 2015, with the formation and track of the 2015 MOV being predicted better than the other cases. Our findings show that the synoptic-scale performance of UFS S2S prototypes is sensitive to the accurate representation of tropical convection. Through the analysis of the Somali jet index, we highlight the potential interactions between precipitation and monsoon dynamics, which still pose challenges for accurate sub-seasonal weather prediction in the monsoon regions.
Shreyas Dhavale is a recipient of the NOAA Weather Program Office Innovation for Next Generation Scientists (WINGS) Fellowship and a PhD Candidate at the Department of Marine, Earth, and Atmospheric Sciences at North Carolina State University.
His PhD research is on the ‘Monsoon Onset Vortex (MOV),’ which is a synoptic weather system that forms in the Arabian Sea in some years during the onset of the Indian Summer Monsoon. He studies the origin, structure, and predictability of the MOV in Reanalysis data, Satellite observations, and numerical models such as WRF and UFS.
Shreyas is also a recipient of the 2024 John S. Irwin Award for Scientific Excellence from the Department of Marine, Earth, and Atmospheric Sciences at North Carolina State University.
