Incoming south-west monsoon continues to linger along the Sri Lankan latitudes, still deprived of the sea-borne circulation that would normally propel it northward into Kerala. Such a ‘vortex’ now appears unlikely to form before month-end, delaying the season’s decisive advance into mainland India.
Nor is there support forthcoming from the upper atmosphere. The Madden–Julian Oscillation (MJO), an eastward-moving tropical pulse that often shepherds monsoon onsets, has already moved out of the Indian Ocean into the western Pacific. Current global projections suggest it may not return until around June 18.
This roaming equatorial wave of clouds and rainfall, recurring every 30 to 60 days, is closely linked to the birth of tropical storms and strengthening of the monsoon current and its onset under its footprint. Its absence has left the Arabian Sea branch of the monsoon without its usual atmospheric momentum.
