Monsoon arrives, normal rains likely
FORECAST Monsoon rainfall critical for summer sowing by farmers
nNEW DELHI: The south-west monsoon made an onset over Kerala on Monday morning, keeping its normal arrival date of June 1, with heavy to very heavy rains and strong southwesterly winds blowing in parts of the state.
The India Meteorological Department (IMD) forecast on Monday that monsoon this year was likely to be “normal” at 102% of long period average (LPA) with a model error of (+/-) 4%.
According to IMD’S second long-range forecast update for the monsoon, north-west India is expected to receive excess monsoon rainfall at 107% of LPA; Central India is likely to get 103% of LPA, while south peninsula and north-east India area likely to receive 102% and 96% of LPA respectively with a model error of (+/-) 8%. The forecast added that there is a 41% probability of a “normal” monsoon, 25% probability of an “above normal” monsoon, and only 5% probability of deficient rains.
In its first long-range forecast released in April, IMD predicted that monsoon rain will be 100% of LPA this year.
Normal monsoon is defined as 96 to 104% and above normal as 104 to 110% of LPA.
Monsoon rains are critical for farmers in India, where nearly half the people directly or indirectly depend on agriculture for a living. Around 60% of the country’s net-sown area does not have any form of irrigation. Millions of farmers wait for rains to begin the summer sowing.
“We are expecting very good rains this year. As you can see the forecast is skewed towards the positive side,” said M Rajeevan, secretary, Union ministry of earth sciences.
According to global weather experts, El Nino Southern Oscillation neutral conditions are prevailing over the equatorial Pacific, and neutral Indian Ocean Dipole (IOD) conditions are prevailing over the Indian Ocean. El Nino is a climate pattern characterised by high sea surface temperatures in the tropical Pacific Ocean. El Nino years in India are linked to below-normal monsoon rains and higher-than-normal heat waves. Last year, weak El Nino conditions prevailed, leading to delayed onset of monsoon.
Global models are also indicating that cool Enso conditions are likely to prevail this monsoon with some possibility of development of weak La Nina conditions, characterised by low sea surface temperatures across the eastcentral Equatorial Pacific in the later part of the monsoon season. “La Nina is good for the monsoon unlike El Nino. This is good news,” said M Mohapatra, director general, IMD.
“We can’t say anything this year because we haven’t made a forecast. Conditions are favourable for a good monsoon because of Enso neutral conditions. In fact, personally I think there will be above normal rains,” said Mahesh Palawat, vice president (climate and meteorology) at Skymet Weather.
According to IMD’S national weather forecasting centre, the monsoon has already advanced into all of the South Arabian Sea; Lakshadweep, most parts of Kerala and parts of Tamil Nadu.
“Kerala received very good rains and monsoon is advancing well. The winds are south-westerly and westerly, very strong winds. There are convective clouds over south-east Arabian Sea. All parameters for monsoon onset are now met,” said K Sathi Devi, head of National Weather Forecasting Centre. He added that the monsoon winds were strengthened by the depression formed over south-east Arabian Sea, which is likely to develop into a cyclone on Tuesday. The south-west monsoon normally sets in over Kerala around June 1. It advances northwards, and covers the country around July 15.