The heavy monsoon over India and adjoining Bangladesh may ease by the weekend, according to an outlook from the Australian Bureau of Meteorology.
The currently busy monsoon is underwritten by a periodical Madden-Julian Oscillation (MJO) wave, which has established itself over West Indian Ocean and adjoining Arabian Sea, the Bureau said.
The MJO is likely to weaken by the weekend, loosening its influence over the monsoon and weakening it in the bargain, but not before it has poured it down heavy over the West Coast and East India.
The monsoon, the Bureau said, is expected to continue this week and isolated heavy rainfall may lead to more flooding or exacerbate existing flooding. It is forecast to slowly ease over Bangladesh and surrounding Myanmar over the weekend.
Heavy rainfall has already been reported around North Bangladesh/Indian border. But the northernmost limit of the monsoon has made little progress over Central and East India in the past fortnight but has reached Gujarat State in the West.
Meanwhile, for the second time during this season, a promising cyclonic circulation over North-West Bay of Bengal has lost its way and strayed into South Bangladesh, India Met Department (IMD) said.
Thunderstorm alert
This, as the Australian Bureau noted, may go to exacerbate conditions over a geography that has been at the receiving end of the monsoon thus far during the season. Meanwhile, IMD said that pre-monsoon thunderstorm activity has already commenced over parts of part of North-West India ahead of the better organised seasonal rains.
Advance of monsoon is likely over most parts of North-West India, including the National Capital, during Thursday to Saturday (June 28 to 30), which is around the normal timeline. This would make for a smart shift in the fortunes of the monsoon that had stalled over Mumbai and Peninsular India during a critical week-long period beginning June 13.
An East-West trough extending from Punjab to East Assam across Uttar Pradesh, Bihar and the hills of Bengal too has taken shape, which would streamline itself to serve as the monsoon trough.
Crucial features
This would be the spine of the monsoon in North India, and when fully developed, would lie extended from West Rajasthan to Head Bay of Bengal to anchor the monsoon. This is as crucial a monsoon feature as the offshore trough that lies along the West Coast, currently extending the full length from South Gujarat to Kerala, signalling strong monsoon conditions.
Meanwhile, IMD has forecast for today (Tuesday) heavy to very heavy rain at isolated places over Jharkhand, plains of Bengal, Odisha, Assam, Meghalaya, Nagaland, Manipur, Mizoram and Tripura over East and North-East India.
A similar forecast is held out for the day for an already rain-battered East Gujarat, Konkan, Goa and Coastal Karnataka along the West Coast.
Heavy rain is likely at isolated places over Rajasthan, West Madhya Pradesh, Chhattisgarh, Bihar, hills of Bengal, Sikkim, Arunachal Pradesh, Madhya Maharashtra, and, in the South, over North Coastal Andhra Pradesh and South Interior Karnataka.