Rain deficit worsens as Met mulls review of monsoon forecast bl-premium-article-image

Vinson Kurian Updated - December 07, 2021 at 12:33 AM.

Satellite image taken on August 3, 2018. (10.14 IST)

The rain deficit for the country as a whole worsened to -7 per cent as North Interior Karnataka fell afresh within the threshold level (-20 per cent) yesterday and deficits elsewhere inched up.

Particularly noteworthy are Lakshadweep (-44 per cent) and Rayalaseema (-42 per cent), which have posted the highest two individual deficits among the 36 Met subdivisions. 

CUMULATIVE IMPACT

Arunachal Pradesh (-35); Assam and Meghalaya (-31); Nagaland-Manipur-Mizoram-Tripura (-24) and, to some extent, hills of Bengal and Sikkim (-17) complete the scenario in North-East India.

India Met Department (IMD) considers a deviation from normal of up to 20 per cent to either side (-20 to +20) as normal. So hills of Bengal and Sikkim are 'rainfall normal' despite the deficit.

Similarly, Saurashtra and Kutch (-19); Himachal Pradesh (-14); East Uttar Pradesh (-13); and Marathawada (-11) find themselves in the 'normal category.' 

Cumulatively, all these masked deficits, along with persisting obvious ones in Jharkhand (-24 per cent) and Bihar (-22 per cent) have been instrumental in pulling back the monsoon performance thus far.

Meanwhile, after private forecaster Skymet, IMD is mulling a review of the monsoon forecast for the second half of the monsoon (August and September) with a possible downgrading likely.

BAY TO STAY 'ACTIVE'

Agency reports quoted KJ Ramesh, Director-General, as saying that IMD is at it, and will soon issue a statement. But he noted that the monsoon has spread well to all agriculturally-important regions.

Skymet had said on Wednesday that the June to September season would be at 92 per cent of the Long Period Average (LPA). It had earlier forecast rains to be 'normal' or 100 per cent of the LPA.

It attributed the review of forecast the unanticipated shortfall in July and expected weak rains during the whole of August likely resulting from adverse conditions developing in the far-off Equatorial Pacific.

But global forecasts continue to suggest that the Bay of Bengal would remain in an animated state until mid-August and throw up circulations that cross the East Coast and head into hinterland, bringing rains.

Extended forecast outlook by IMD too suggests a similar scenario when rains revive over most parts of the country in phases, except over Rajasthan, Gujarat and parts of Peninsular India until August 16.

RAINS MAY RETURN

North-East India, East India and parts of adjoining Central India, the plains of North-West India as also parts of the West Coast may stand to receive varying amounts of rainfall during this phase.

This should apparently keep at bay fears about a 'break monsoon,' an inevitable phase of monsoon rains drying up over large parts of the country for a prolonged period, until mid-August.

According to the European Centre for Medium-Range Weather Forecasts, the rains would sustain over the North-East and East India during the next three days and perhaps stay so for two more days as well.

The West Coast would come back to life, though not with the same intensity as witnessed earlier during July. Rains are seen less pronounced over Coastal Karnataka and Kerala to the South of the coast. 

An ensemble model of the US Climate Prediction Centre too has persisted with its outlook for the Bay to remain active until mid-August, though clues about the second half of the month are still awaited.

Published on August 3, 2018 05:52