As predicted by India Met Department (IMD), the low-pressure area over North-East Bay of Bengal intensified twice over to become a depression last night.
It is likely that the system would have crossed the Bangladesh coast around midnight itself, bringing a wave of heavy to very heavy over that country and the contiguous North-Eastern States of India.
Active in N-E
The northern limit of monsoon was unchanged across Thane (including Mumbai), Ahmednagar, Parbhani, Yeotmal, Brahmapuri, Rajnandgaon, Bhavanipatna, Puri, Agartala, Lumding, and North Lakhimpur.
The depression in the Bay is expected to help the monsoon to get a move in the East and North-East of India, where it has been lagging for quite some time now.
The IMD assessed that conditions are becoming favourable for its advance into some more parts of Vidarbha, Chhattisgarh and Odisha, some parts of West Bengal and Sikkim and remaining parts of the North-Eastern States by tomorrow. The subsequent couple of days could seen the monsoon check into some more parts of Bengal, Odisha and some parts of Jharkhand and Bihar, where it should have normally reached yesterday.
The IMD has forecast fairly widespread to widespread rainfall activity with isolated heavy falls along West Coast, the North-Eastern States, hills of Bengal and Sikkim until the weekend.
Reduced rainfall
But rainfall over the rest of Peninsular India, Central and East India is likely to reduce further. Isolated to scattered rainfall is likely over these areas during this period.
Meanwhile, the pre-monsoon feature represented by the East-West over North India ran down from Punjab to centre of the depression over North-East Bay and adjoining Bangladesh. This cut through Haryana, Uttar Pradesh, Jharkhand and Gangetic West Bengal, and would convert itself as the crucial monsoon trough, the spine of the monsoon, when monsoon establishes fully.
But this would require the formation of a ‘low’ in the Head Bay, and the North-West end of the land-based trough connect with West Rajasthan. There is no indication as to exactly when this ‘low’ can form, though the US National Centres for Environmental Prediction has been hinting sometime after June 20.
The IMD, on its part, as already indicated that the monsoon in a weaker phase till then, though this is to be expected once the monsoon completed its an productive onset phase.