As the South-West monsoon prepares to withdraw from West Rajasthan, the US National Weather Services has put the Arabian Sea under watch for enhanced weather activity early next month ahead of the arrival of the North-East monsoon.
It has pointed to the possibility of a weather system developing around Sri Lanka, the adjoining Lakshadweep Sea and Maldives between October 4 to 9 gathering strength and propelling towards the Oman-Yemen coast from October 8 to 12.
Trough over bay
The track around Sri Lanka, apparently directed towards Maldives-Lakshadweep before moving further away, resembles the one ‘discovered’ by the very severe cyclone Ockhi last year. The US agency has been hinting at this possibility over the last few days, though it is too early to take a call on the eventuality just yet. If this were to materialise, it could bring the North-East monsoon into the South Peninsula.
Interestingly, the India Met Department (IMD) has been tracking a cyclonic circulation over the South-West Bay of Bengal off the Tamil Nadu coast, having moved in from the upstream South-East over the past couple of days.
It has also marked out an East-West trough across the South Peninsular India (passing through Puducherry in Tamil Nadu) in which the cyclonic circulation is embedded.
The IMD’s windfield projections shows not one circulation, but two — around Maldives and upstream around Sri Lanka — around October 6. Its extended forecast bulletin for the period September 28 to October 4 doesn’t mention anything about this, though. But it sees above-normal rainfall for Kerala, Tamil Nadu, Karnataka, the southern parts of Maharashtra, Goa, AP and Telangana between September 28 to October 4.
Rain for south
In fact, rain/thundershowers would have already established over the South Peninsula and North-East India by then as part of the monsoon transition phase. IMD forecasts leading up to September 28 indicate the same.
For instance, heavy to very heavy rain has been forecast over Assam and Meghalaya on Thursday (September 27) while it will be heavy over the hills of Bengal, Sikkim, Rayalaseema, South Interior Karnataka, Tamil Nadu and Kerala.
Thunderstorms accompanied by lightning may strike over South Chhattisgarh, Jharkhand, the plains of Bengal, Odisha, Assam, Meghalaya, Madhya Maharashtra, Marathawada, Konkan, Goa, Coastal Andhra Pradesh, Telangana, Rayalaseema, North Interior Karnataka and Kerala.
The forecast for Friday said heavy to very heavy rain is likely over Tamil Nadu and Kerala while it will be heavy over Assam, Meghalaya, Nagaland, Manipur, Mizoram, Tripura, Coastal and South Interior Karnataka.