A fresh low pressure area is likely to form over Bay of Bengal(BoB) around middle of next week. Unlike June which hosted only one low pressure area, this fresh system will form over Head BoB, in quick succession to the earlier one on 11thJuly over the northwest BoB. A cyclonic circulation is forming over top region of BoB on 20thJuly and is likely to organize further in to a low pressure area on 21st July over the same region.
Southwest Monsoon has gone a little subdued( except along West Coast) and this phase will soon get over with the monsoon trough establishing along the Indo Gangetic plains. With initial signs appearing on the 17th July, it become significantly marked on 18th July and runs across Haryana, Delhi, Uttar Pradesh and Bihar. Heavy to very heavy rainfall with flooding rains at few places, is expected over Delhi and West Uttar Pradesh on 18th July. Thereafter, this trough dips in the Bay of Bengal and a cyclonic circulation is likely to form on 20thJuly over North Bay of Bengal and adjoining Bangladesh and West Bengal. This will rapidly organize to turn in to a low pressure area on 21st July over the same region, partly over land and the rest over Sea. This weather system will move inland across West Bengal, Odisha, Jharkhand, Chhattisgarh, Madhya Pradesh and Maharashtra over the next 4 days.
Intense and wide spread weather activity will commence on 20th itself over the coastal states to start with later spreading over most parts of neighboring states. Heavy to very heavy rainfall is expected over Chhattisgarh, East Madhya Pradesh and Vidarbha between 21st and 23rd July. Further travel of this system will activate the monsoon trough once again to cause another spell of heavy rains over Delhi, West Uttar Pradesh and Haryana. As it usually happens, the formation of this system will activate vigorous monsoon conditions over Konkan region between 19th and 24thJuly. Mumbai will possibly head for second spell of heavy to very heavy rains of this month during this period.
Southwest Monsoon is running with a seasonal deficiency of 6% ( 01st June-16th July) and the month of July by itself is having a shortfall of 25% rainfall. This active spell of monsoon between 20th July and 31st July, without any long and significant break in between, is expected to sail the monsoon closer to its normal rainfall. Active monsoon conditions are also likely to spill over to the 1st week of August.