The southwest monsoon has officially advanced into Sri Lanka, clearing the final atmospheric hurdle before its much-anticipated arrival over the Kerala coast. However, despite earlier predictions of an onset by May 26, the India Meteorological Department (IMD) has confirmed that the monsoon is yet to set in over the southern Indian state.
According to the IMD’s latest bulletin on Wednesday, while the monsoon has progressed into parts of the southwest and southeast Arabian Sea, the Lakshadweep area, and the Bay of Bengal, the conditions necessary for declaring an onset over Kerala have not been met . Weather experts now suggest that the rains could arrive in the state between June 2 and June 10 .
Why the delay?
The delay in the monsoon’s onset is being attributed to a combination of weakening wind patterns and the persisting impact of the El Nino weather phenomenon.
For the IMD to officially declare the onset of the monsoon over Kerala, a strict set of criteria must be fulfilled: at least 60% of 14 designated weather stations in the state must record rainfall of 2.5 mm or more for two consecutive days, accompanied by specific wind speed and cloud formation conditions .
Currently, while Sri Lanka has received widespread showers — a traditional precursor to the Indian monsoon — the monsoon winds over the Indian Ocean remain weak. “For the onset of monsoon to be officially declared over Kerala, three parameters are crucial: rainfall, sufficiently deep monsoon winds over the Indian Ocean and cloud patterns… monsoon winds over the Indian Ocean remain weak and have not yet reached Kerala,” said Akshay Deoras, a research scientist from the University of Reading .
Compounding this is the looming threat of El Nino. Meteorologists have warned that the El Nino phenomenon over the central Pacific Ocean has formed much earlier than expected this year, which historically correlates with weaker monsoon rainfall in India .
The outlook for Kerala
Despite the official delay, the IMD has forecast light to moderate rainfall accompanied by thunderstorms, lightning, and gusty winds over Kerala, Mahe, and Lakshadweep between May 26 and May 29 . A yellow alert has been issued for these regions for the next four days.
Weather models suggest that the atmospheric alignment required for a sustained monsoon onset is expected to become favorable around June 1, with a plus or minus two-day error margin. “Based on the current model guidance, it appears that Kerala may have to wait until around June 1… for a more favourable and sustainable monsoon onset set-up to develop,” said independent weather expert Abhijit Modak .
A delayed seasonal forecast
The delayed onset marks a slip from the IMD’s earlier forecast, which had predicted the monsoon to hit the Kerala coast around May 26—about five days earlier than the normal date of June 1 . The normal date for the monsoon onset over Kerala is June 1 .
In a statement, the IMD noted, “Conditions are favourable for further advance of southwest monsoon into some more parts of southwest and southeast Arabian Sea, Lakshadweep area, southwest, eastcentral and westcentral Bay of Bengal… during the next 2-3 days” .
With the monsoon having cleared Sri Lanka, the stage is set for its final approach to the Indian mainland. However, farmers and residents will have to wait a little longer for the skies to open up over the Kerala coast.
