After a delayed onset, the monsoon is on a familiar roller-coaster ride this June, leaving a deficit that threatens to breach the seven-year record of 42 per cent seen in 2014.

With a week to go, June has already totted up a deficit of 38 per cent, and unless a dramatic recovery takes place, it could potentially add to the list of ‘failures’ of the four-month season.

The second-worst deficit in June over the last seven years was in 2012 (28 per cent), a ‘milestone’ that has already been breached by a significant margin. A lot will hence depend on the monsoon realisation during this week.

Combined with a poor pre-monsoon season (-25 per cent; see table ), another forgettable June is adding to the lack of availability of water as storage levels hit new lows across the country.

June’s share of monsoon rainfall during the four-month season is 17-18 per cent. September generates a similar amount of rain. July (33 per cent) and August (30 per cent) are the two rainiest months.

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Vayu blow

The week-long delay in the onset of the monsoon, and the initiation of the very severe cyclone ‘Vayu’ early into the season had disrupted its spread and progress.

It took last week’s fresh low-pressure area over the north-west Bay of Bengal to revive the monsoon current, a process that is still in progress, though not supported by expected spatial and temporal coverage.

The ‘low’ has weakened into a rudimentary cyclonic circulation, and lies over east Madhya Pradesh, backed up by a land-based trough from north-west Rajasthan to Nagaland across east Rajasthan, north Madhya Pradesh, Bihar, the hills of Bengal and Assam. But the trough is of not much help unless its south-eastern tip dips into the Bay of Bengal. And this can happen only with the formation of another ‘low’ in the Bay.

The next ‘low’, and a strong one at that, is expected to form over the ‘head’ Bay (northern-most part of the Bay) — which is the ideal location with regard to prospects of good rain for North India — in the early part of July.

 

 

Read more: Sluggish monsoon - 84% of meteorological subdivisions record deficit rainfall

 

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