Hopes high for a good monsoon

Indian Institute of Tropical Meteorology says there is a 54% probability that rainfall during the monsoon season this year will be 10 mm-per-day more than normal


A normal monsoon will help restore agricultural productivity, enhance rural demand and boost macroeconomic prospects. Photo: HT
A normal monsoon will help restore agricultural productivity, enhance rural demand and boost macroeconomic prospects. Photo: HT

New Delhi: Weather scientists said they may have spotted signs of a normal, if not a good, rainy season this year, sparking hope among farmers and policymakers alike after two successive bad monsoons.

With just three weeks to go for the India Meteorological Department’s (IMD’s) much-awaited monsoon forecast, scientists at the Indian Institute of Tropical Meteorology (IITM), under the ministry of earth sciences, have signalled the highest probability yet of better-than-normal rainfall in the June-September monsoon season.

According to the Pune-based institute, there is a 54% probability that rainfall during the monsoon season this year will be 10 mm-per-day more than normal.

IITM’s seasonal range prediction is based on its Climate Forecast System Version 2 (CFS v2), said to be more accurate than other models. The forecast is based on February observations.

A normal monsoon will help restore agricultural productivity, enhance rural demand and boost India’s macroeconomic prospects. India bore the brunt of the 2015-16 El Nino weather phenomenon, with a 14% rainfall deficit in the south-west monsoon last year, after which 10 states declared drought.

This followed a 12% rainfall deficit in the 2014 monsoon season. At the same time, both these years also suffered from unseasonal rainfall in March and April. The erratic weather led to declining growth rates as consecutive crop failures resulted in a 0.2% contraction in agricultural output in 2014-15. Poor rains also result in higher inflation and the possibility of a good monsoon this year increase the chances of the country’s central bank retaining its easy money policy.

IITM published a paper late last year on the accuracy of the CFS v2 model. “We have shown that monsoon forecast over the Indian region during the June-September period is reliable from initial observations in February,” said Rajib Chattopadhyay, lead contributor of the study.

On 1 April, Weather Risk Management Services Pvt. Ltd (WRMS), a private weather forecasting and risk assessment agency, provided a long-range forecast based on March observations saying monsoon 2016 may end up on the positive side of normal, with well-distributed rainfall everywhere except the North-East.

WRMS indicated that El Nino, a weather phenomenon that results from the warming of Pacific Ocean regions and is associated with drier-than-normal conditions in India, will continue to weaken over the coming months, returning to neutral by early summer of this year. There is also a chance of La Nina developing by November, it said, adding that these signals are favourable to above-normal monsoon rainfall over the country during June-September.

The La Nina weather phenomenon, also known as the anti-El Nino, is associated with higher-than-normal rainfall in India.

WRMS processes data from the US’ National Oceanic and Atmospheric Administration and CFS v2 model and adds statistical interpretations to provide long-range weather forecasts to clients.

Kanti Prasad, former deputy director at IMD, said: “It is too early to give exact probabilities, but based on observations made in March, there are broad indications of a positive monsoon, with the weakening El Nino being the main driving force.”

But IMD officials insisted that it is not possible to put out an accurate forecast right now and said the agency will issue one by the end of April.

The south-west monsoon accounts for more than 70% of the annual rainfall in India, where nearly 53% of crop area is unirrigated.

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