Onset of southwest monsoon over the south Andaman Sea on Saturday night was masterminded by raging super typhoon Dolphin in the northwest Pacific.
The super typhoon is now the predominant weather system under the command area of the larger Asian monsoon and has been instrumental in ratcheting up wind speeds over not just the northwest Pacific but also the Indian Ocean.
The Pacific and Indian ocean basins spanning tens of thousands of sq km form apart form an extended area of influence under a single monsoon system for all practical purposes.
This is why the southwest monsoon is considered a planetary phenomenon, the largest and most spectacular arm of which is the one that plays over the Indian subcontinent.
The onset phase in the Bay is forecast to hold strong over the next two to three days in tandem with the peaking of the super typhoon.
Heavy rains The system would start weakening to the south of Japan when the activity over the Bay of Bengal is forecast to peak over. Wind speeds in the central Bay of Bengal would have touched beyond 50 km/hr before this happens, forecast outlook says.
During this phase, the heavy to very heavy rains over south peninsular India would have shifted to northeast India and adjoining east India, Bangladesh, Myanmar and adjoining western Thailand.
Winds are forecast to wind down over the Bay by May 23/24 and the heavy rain over south peninsula would lift by that time.
The cross-equatorial monsoon flows that turn off the Somali coast and those in the Bay may start picking up again post May 25, as per these forecasts.
Onset over Kerala Un Saturday, India Met Department announced that the monsoon had arrived at its first port of call in Indian territorial waters over the Andaman and Nicobar Islands.
From here, it is normally 10 to 12 days for the seasonal rains to hit mainland India first at the southwestern coast of Kerala via Sri Lanka.
But indications are that the monsoon might run up the distance earlier than expected, sometime towards the earlier limit of the May 26-June 3 window that India Met has set.
The Met said that conditions are favourable for the monsoon to enter into some parts of south Bay of Bengal and east-central Bay of Bengal, and remaining parts of Andaman Islands and the north Andaman Sea during the next two days.