The IMD said in a statement that the monsoon, a lifeline for Indian agriculture, will set in on May 27, while Skymet said the onset would happen on May 26. The arrival is against the normal onset of June 1 every year.
While the IMD said its model had an error of plus or minus four days, Skymet said its model’s error was plus or minus three days. BusinessLine reported on May 2 that the monsoon, starting on June 1 and ending on September 30 annually, would reach Myanmar between May 8 and 13 against the normal date of May 18, quoting the Myanmar Department of Meteorology and Hydrology.
Low-pressure area helps
The monsoon’s early setting in has been helped this year by the formation of a low-pressure area over the South Andaman Sea last week that intensified into a depression, an update by the Myanmar Department of Meteorology and Hydrology said.
The IMD said initial monsoon rains are being experienced over the South Andaman sea and the monsoon winds have advanced north-westwards across the Bay of Bengal.
As per the normal dates of themonsoon onset, the South-West monsoon advances over the Andaman Sea around May 22, the IMD said.
Past data suggest that there is no association of the date of monsoon advance over the Andaman Sea either with the date of monsoon onset over Kerala or with the seasonal monsoon rainfall over the country, the IMD said.
Asani’s enabling role
Earlier, Skymet said in its outlook statement that the onset process is chiefly controlled by the oceanic conditions, both in the Arabian Sea and the Bay of Bengal. Recent cyclone ‘Asani’ enabled the monsoon stream to lock in over the Bay, earlier than normal. Also, the remnant of this storm, as a depression over Peninsular India, has been instrumental in initiating the cross-equatorial monsoon flow.
The combined influence has scared away the obstructing presence of a seasonal anti-cyclone from over the central parts of the Arabian Sea, an essential condition for ingress of the monsoon flows. This will also be assisted by an MJO (Madden Julian Oscillation) wave entering the Indian Ocean, albeit with low amplitude. Pre-monsoon showers will be extensive and powerful over Kerala, the private forecaster said.
This year, the probability of a normal monsoon is 40 per cent as per IMD’s forecast, while Skymet has pegged the probability at 65 per cent. The official weather forecaster had also said there is a 26 per cent chance of below-normal monsoon, while the Skymet put this at 25 per cent.
Both forecasters have ruled out the possibility of excess monsoon rainfall this year and deficient rainfall in September.
Key to farm output
A normal monsoon is essential for good agricultural production, which has been witnessing new highs since 2016-17. During the current crop year (July 2021-June 2022), the Ministry of Agriculture, in its second advanced estimates, projected total foodgrains production at 316.06 million tonnes (mt) against 310.74 mt last year.
However, in view of the intense heatwave across the country since March the production will likely be lowered.
Kharif crops production depends on the south-west monsoon and had made up 60 per cent of total agricultural output at one point in time. However, with unseasonal rains benign experienced in September, October and November over the past few years, rabi production has tended to exceed kharif output, particularly with wheat topping 100 million tonnes. This season, it could be lower, though.
A good crop — either kharif or rabi — helps lift the rural economy with improved sales of white goods, fast-moving consumer goods, two-wheelers, cars and gold. This, in turn, helps the country’s overall economy to perform well.
May 13, 2022