After its initial forecast of "above normal" rainfall, Skymet, a private weather forecasting agency has revised its prediction saying Southwest Monsoon will be "normal" this year.
According to Skymet Weather, the initial surge in the Monsoon rains can be attributed to the transition of El Nino into the neutral phase.
However, Indian Ocean Dipole (IOD) has not influenced the Monsoon 2016 so far, as it has been negative since the beginning of the season. Now, the Madden Julian Oscillation (MJO), which was earlier travelling in the favourable zone, is no longer supportive for Monsoon rains.
The West Coast remains inactive in absence of significant weather systems. Besides this, Monsoon is also subdued over South Peninsula along with Maharashtra.
Though back to back weather systems in North Bay of Bengal have been giving heavy rains over East and Central India, Monsoon over remaining parts of the country has been subdued.
As a result, the actual rainfall is not living up to the daily rainfall figures.
According to the India Meteorological Department (IMD), the weather deficiency has dropped to one per cent and 16 per cent of the country is witnessing "deficient" rainfall, 70 per cent "normal" and 14 per cent "excess".
A 'positive IOD' is associated with cooler than normal sea-surface temperatures in the eastern equatorial Indian Ocean and warmer than normal sea-surface temperatures in the western tropical Indian Ocean. The opposite phenomenon is called a 'negative IOD', and is characterised by warmer than normal SSTs.
El Nino is the unusual warming of sea-surface Pacific waters off the South American coast. The MJO, on the other hand, is a moving system of wind, cloud and pressure that brings rain as it circles around the equator.
"As of now, the IOD remains negative and the MJO is no longer prevailing in the favourable zone for India. El Niño, which wreaked havoc on the Indian Monsoon last year, has finally entered the neutral phase but we still have to wait for few more months to see if it may turn into La Niña," said Jatin Singh, CEO, Skymet.
Monsoon rains in July performed better, as the actual rains in the month settled at 107 per cent of Long Period Average (LPA), the Skymet said.
"Rains picked up pace further as we entered into August. As a result, Monsoon progressed steadily in the initial 10 days. The cumulative countrywide Monsoon rains had reached 103 per cent in the first week and maintained the surplus status till August 12.
"Thereafter, rains reduced considerably along the West Coast and Peninsular India, leading to gradual decrease in rain surplus. As on August 18, the cumulative countrywide Monsoon rain stands at 100 per cent," the Skymet said.
However, September is expected to give better rainfall.
Photograph: Ajay Verma/Reuters
