Why this year's monsoon is 'deficient': 5 key points you need to know
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Why this year's monsoon is 'deficient': 5 key points you need to know

India’s met department has lowered its rainfall forecast from “below-normal” to “deficient”, prompting the government to prepare for a drought-like condition.

india Updated: Jun 04, 2015 12:14 IST
HT Correspondent
HT Correspondent
Hindustan Times

India’s met department has lowered its rainfall forecast from “below-normal” to “deficient”, prompting the government to prepare for a drought-like condition.

The revision on Tuesday by the India Meteorological Department (IMD) – which had forecast a “below normal” monsoon in April – will potentially toughen challenges for the NDA government that is already battling a farm crisis triggered by unseasonal rains in March-April.

Here’s a look at key points about this year’s monsoon:

What does the met department’s forecast say?

In its second long-range forecast, the IMD said on Tuesday the country is likely to get only 88% of normal rainfall this monsoon season, down from the 93% forecast a month earlier.

Rainfall is likely to be well below normal in every region, with northwest India, including Delhi, likely to get only 85% of normal rainfall.

The IMD said there is now a 66% chance that the rainfall will be “deficient” (below 90% of a 50-year average), and only a 7% chance that it will be “normal” (96% to 104% of the long-period average).

What do “deficient”, “average” and “normal” rainfall mean?

In India, the “average” rainfall or the long-period average (LPA) is the average of rainfall between 1951 and 2000, which is 89 cm.

A normal monsoon is one when rainfall is between 96% and 104% of the LPA.

An “above normal” monsoon occurs when rainfall remains between 104% 110% of the LPA.

If the rainfall is more than 110% of the LPA, then it is called “excess”.

Rainfall is considered “deficient” when it is less than 90% of the LPA.

What is El Nino and how does it affect Indian monsoon?

The IMD attributed the downgrade in its forecast to the strengthening of the El Nino system in the equatorial Pacific Ocean.

El Nino refers to a condition in which ocean temperatures in equatorial Pacific regions, off the western coast of South America, become unusually warm.

El Nino is known to have an impact on the Indian monsoon, besides affecting a lot of other weather events worldwide. There is a strong co-relation between an El Nino event and a poor monsoon.

D Sivananda Pai, head of the long-range forecasting division of IMD, said the assessment of the El Nino was much better now as compared to when the first forecast was made in April.

“The latest forecast from IMD-IITM (Indian Institute of Tropical Meteorology, Pune) coupled model indicates El Nino conditions are likely to strengthen further and reach moderate strength during the monsoon season. There is about 90% probability of El Nino conditions to continue during the southwest monsoon season,” the IMD said.

What is the region-wise rainfall distribution predicted?

Northwest India is expected to receive 85% of the LPA of rainfall while the predicted rainfall for central India is around 90%.

South India is expected to receive 92% of the average rainfall while the prediction for the northeast is 90%.

All the probable scenarios have an error percentage of plus or minus eight.

This graph explains the scenario across the country


What steps is the government taking?

Cabinet secretary Ajit Seth chaired a meeting of secretaries on Tuesday to review the situation after the met department lowered its prediction. “All ministries and states have been asked to remain prepared as the possibility of drought looms large,” a government official told Hindustan Times on condition of anonymity. A note prepared for the meeting said: “Below normal rainfall and development of EL Nino effect assumes more significance because last year was also a drought year (88% of long period average rainfall) and farmers have already faced a lot of distress in rabi crop because of unprecedented hailstorm and unseasonal rainfall in February, March and April.”

Secretaries of departments such food and public distribution, home, earth sciences, agriculture, water resources, expenditure, rural development, power and environment, the railway board chairman and the Niti Aayog CEO participated in the meeting.

(With input from Reuters)

First Published: Jun 03, 2015 12:04 IST