A full and frontal monsoonal assault on India's west coast is being delayed by a brief distraction to the flows yet again, over the familiar waters off Oman and Yemen in the Arabian Sea.
This has mostly to do with the sheer strength of the flows, showing how the larger monsoon system has been keeping good health, as they turn furiously off the Somalia and Yemen coasts towards India.
'ROGUE' CIRCULATION
In turn, a part of the flows is being appropriated by a circulation off Somalia and Yemen as they take a U-turn there, causing only the rest to reach mainly the Kerala coast for now.
This is why the monsoon has not been able to move further on from its alignment along Shirali, Hassan, Mysuru, Kodaikanal, Thoothukudi and Aizwal in Mizoram for a few days now.
But this rogue circulation is expected to die out over the next three days (by June 6, Wednesday) when the flows would be let free to make a full-blooded run towards India's entire West Coast.
It is a testimonial to the good bearing of the monsoon system that it has been holding out to the 'provocation' from far out in the Arabian Sea and shaping up in the Bay of Bengal. Its Bay arm made an onset over the North-East in the interregnum and is preparing to expand coverage over the next 24 hours, the India Met Department (IMD) said.
Meanwhile, it is becoming clear that the Bay and the Arabian Sea must thank the 'persuasive skills' of a tropical depression in the neighbouring South China Sea for their expected deliverance.
HELP FROM PACIFIC
The flows across the Arabian Sea and the Bay would strengthen from Wednesday in tandem with this depression as it moves from its current location off Hanoi, Vietnam, towards South-West China.
It is on the trail of these flows that helpful circulations form to anchor them over these seas and direct the rain bands back to the mainland across Central and Peninsular India.
This would make for a strong monsoon onset over Mumbai around the scheduled date of June 10 (there could be a surprise on the upside here) and plentiful rains over Central India during this period.
In fact, it would also see a monsoon system (low-pressure area or depression) forming in the 'head' Bay, coinciding with the growth of a follow-up circulation in the South China Sea into a typhoon (cyclone).
This is in line with the outlook of the European Centre for Medium-Range Weather Forecasts until June 10. The IMD points to a circulation off Mumbai during this phase, intensifying rains on the West Coast.
Meanwhile, the Thiruvananthapuram Met Office has warned of thunderstorms and gusty winds in Kollam, Alappuzha, Pathanamthitta, Kottayam, Ernakulam, Thrissur, Malappuram districts.