Boys play in rain water in Kozhikode as monsoon hits Kerala on Friday. (PTI)
New Delhi, June 6: The monsoon advanced over Kerala today five days late, the delayed arrival and weak pulse raising the possibility of prolonging Calcutta’s wait beyond the usual June 8 to 10.
The onset dates, however, have no correlation with how much rain India will get over the season, weather scientists say.
The India Meteorological Department (IMD) announced the onset of the monsoon over Kerala after observing just the right combination of rainfall, cloud, and wind conditions that define its arrival over the southwestern part of mainland India.
“It is a weak pulse, but it has arrived,” D. Sivananda Pai, senior meteorologist at the IMD, Pune, told The Telegraph.
“It has to strengthen. We expect this will happen in the coming days. The heat in northern India could help strengthen its flow.”
The northern limit of the monsoon line on Friday passed through Kozhikode in Kerala and Coimbatore and Cuddalore in Tamil Nadu, the IMD said this evening.
It predicted that the monsoon was likely to cover Kerala and extend into Karnataka, Tamil Nadu and the Bay of Bengal within the next three days.
The wind conditions appear favourable for the advance of the monsoon into the Northeast within 48 hours, it said.
The weather agency has also predicted spells of heavy rainfall over Kerala, sub-Himalayan (northern) Bengal and parts of Assam, Meghalaya and Arunachal Pradesh over the next two days.
A normal flow of monsoon winds is generally expected to bring monsoon rain over Calcutta between June 8 and June 10 and across all of Bihar by June 15. But the late onset over Kerala and the weak pulse may delay the monsoon in these states.
In its long-range monsoon forecast issued in April this year, the IMD had predicted that the rainfall across the country as a whole would be 5 per cent below the long-period average for the four-month season from June through September.
Weather scientists are concerned about sea surface temperatures in the equatorial Pacific that have in recent weeks shown a rising trend.
There are concerns that if the Pacific sea surface temperatures exceed levels that scientists call El Nino, India may experience poor rainfall, or even a drought. The El Nino phenomenon has in the past been associated with poor monsoon rainfall.
But senior meteorologists say that multiple factors influence the behaviour of the monsoon, and that historical monsoon records show that the emergence of El Nino doesn’t always translate into a poor monsoon.