Rainfall for the country as a whole has turned out normal once again with two of the four homogenous geographical regions posting a surplus while the two others cut down their localised deficits significantly on Wednesday. Earlier on June 22, surplus rainfall over East and North-East India and western disturbance activity had combined to level the score after the deficit had soared during the first fortnight after monsoon onset.

Bay wakes up from slumber

But the country as a whole fell back into a double-digit deficit with the monsoon taking time to cover Central and North-West India. This has now been made good after the Bay of Bengal woke up from a slumber and sent the monsoon current deep inland into Central India triggering heavy to very heavy rainfall. The shortfall over Central India has been cut down to 10 per cent, and North-West India, to two per cent. The South Peninsula has joined East and North-East India to post a surplus of six per cent while the latter saw its own surplus erode to eight per cent after the monsoon clouds left the region for Central and North-West India.

Nagging deficits linger

Some individual meteorological subdivisions within the four homogenous areas continue to suffer big deficits, led by East Uttar Pradesh (52 per cent); West Uttar Pradesh (48 per cent); plains of West Bengal (46 per cent); Jharkhand (43 per cent); and Kerala (35 per cent), among the worst affected. Madhya Maharashtra (24 per cent); Odisha (22 per cent); Uttarakhand and East Gujarat (21 per cent) are comparably better off. Ongoing rains in the North and South should help fill the deficit to some extent in mostplaces, and entirely so in a few. Expected movement of the monsoon trough to the North of its current alignment and to its normal position will, therefore, tilt the scales accordingly in the next few days.

‘Low’ on way out, successor in

This movement of the trough will bring the belt of heavy rain to both the hills and plains of North-West India, sending some much-needed respite to a rain-deficit State such as Uttar Pradesh. India Meteorological Department (IMD) said the prevailing low-pressure area moved from Gujarat and was parked lover Kutch on Wednesday evening. As expected, it is likely to move further westwards (into the Arabian Sea) and become less marked. But a successor circulation has crawled in from the Bay of Bengal and was located over North Odisha and adjoining Chhattisgarh to hold up one end of the monsoon and help it stay active.

Active monsoon trough

The monsoon trough across North India continues to be active but its western end may start to shift gradually northwards from Thursday, the IMD said. An East-West zone of monsoon turbulence runs across Nashik, Washim, Chandrapur, Kapsi, Bhawanipatna and Bhubaneshwar across Maharashtra, Chhattisgarh and Odisha. The offshore trough has straightened out from Gujarat coast to run as far down as the Karnataka coast, which augurs well for the monsoon over the North Peninsula. This configuration of atmospheric features is expected to drive the monsoon along the West Coast and adjoining Peninsular, Central, North-West and East India into Thursday.

Monsoon enters Pakistan

The US Climate Prediction Centre attributed the strong monsoon to ‘enhanced convection (cloud-building) associated with both La Nina and a visiting Madden-Julian Oscillation (MJO) wave feeding into the Asian monsoon.’ It saw a ‘healthy monsoon’ trough extending from South Asia south-eastward across South-East Asia and the West Pacific. The Pakistan Meteorological Department said the monsoon had entered the country from North-East Punjab, Kashmir and Khyber Pakhtunkhwa on July 1, a day after it covered entire India and extended its reach. Overall, it sees a tendency for above normal precipitation during the season (July-August-September).