Yesterday's hyperactive depression moved east-northeast overnight and is parked early this morning over the plains of Bengal, 60 km west-northwest of Kolkata.
More than 36 hours after its landfall over the Odisha coast, the system shows no signs of weakening, helped as it is with assured supply of moisture from the warm North Bay of Bengal waters.
India Met Department (IMD) expects the rain-generating weather system to keep travelling further to east-northeast, mainly over the North-Eastern States of India and adjoining Bangladesh.
Since it would not be too far away from the coast at any point of time during this slow movement, it would continue to benefit from the moisture feed from the Bay water and retain its intensity.
Any weakening can occur gradually, IMD emphasised, even as the system dumps heavy rainfall over North-East India and Bangladesh.
Southerly winds carrying moisture rise up against the hills of the Eastern Himalayas guarding the North-Eastern States, cool as they are driven up against its heights, and precipitate immediately as rain.
Satellite pictures this morning showed most of the clouding concentrated over North and North-East Bay and adjoining Cox's Bazaar, Chakaria, Chittagong, and Dhaka in Bangladesh.
Cloud over North-East, Bangladesh
Some of the clouding had drifted beyond the Bangladesh boundary to over Aizawl in Mizoram and Silchar in Assam across the North-Eastern States of India.
An IMD update said that heavy to very heavy rainfall occurred over the plains of Bengal until 5.30 pm yesterday evening. Bankura recorded the heaviest rainfall of 17 cm during this period.
As for today, heavy to very rainfall has been forecast over Assam and Meghalaya with the possibility of extreme heavy rainfall at isolated places.
Heavy to very heavy rainfall has also been forecast at isolated places over Arunachal Pradesh, Nagaland, Manipur, Mizoram and Tripura while it will be heavy over the plains of Bengal.
Strong winds with speeds reaching up to 40 km/hr and gusting to 50 km/hr is likely along and off the Bengal coast. Fishermen are advised not to venture out into the adjoining seas.
The focus will now shift to the South Peninsula which is bracing to retire the predecessor South-West monsoon and simultaneously welcome the North-East monsoon.