Onset of monsoon over Kerala likely to be delayed by four days: IMD; pvt forecasters differ

PTI, May 15, 2020, 9:19 PM IST

New Delhi: The southwest monsoon is likely to hit Kerala on June 5, a delay of four days as compared to its normal onset date, the India Meteorological Department (IMD) said on Friday.

The onset of monsoon over Kerala marks the commencement of the four-month long rainfall season from June to September.

Monsoon makes an arrival in Kerala on June 1, according to the normal onset date.

“The onset of the southwest monsoon over Kerala this year is likely to be slightly delayed as compared to the normal date of onset. The monsoon onset over Kerala this year is likely to be on June 5 with a model error of plus or minus four days,” the IMD said.

Private forecasters Skymet Weather and the Weather Company, an IBM Venture, however, differ with the IMD on the onset date, with both predicting an early arrival.

While Skymet Weather said the onset date of monsoon over Kerala is expected to be May 28 with an error margin of plus or minus two days, the Weather Company said monsoon will make an onset over Kerala on May 31.

The IMD said monsoon is likely to arrive over the Andaman and Nicobar Islands around May 16 and May 17, five to six days before its new onset date of May 22 due to a cyclonic storm in the Bay of Bengal.

However, the same cyclone will hinder monsoon’s progress as it moves further.

“Currently, it (a low pressure area, the first stage of any cyclone) is in southeast Bay of Bengal. But as it moves further north and then northeast Bay of Bengal, it will affect the pace of monsoon. This will also have an impact on the onset of monsoon over Kerala,” IMD Director General Mrutunjay Mohapatra said.

Even last year, monsoon had reached the Andaman and Nicobar archipelago on May 18, two days ahead of its then normal onset date of May 20. But due to its sluggish pace, it reached Kerala on June 8. It covered the entire country by July 19.

According to the IMD forecast, monsoon is likely to be normal this year.

The country receives 75 per cent of its rainfall from the southwest monsoon during June to September.

It is not only crucial for farming in the country, but also for replenishing reservoirs, and more importantly to the economy which is still largely dependent on agriculture.

The northeast monsoon is another phenomenon that brings rainfall to Tamil Nadu, Puducherry, parts of Kerala and Andhra Pradesh from October to December.

From this year, the IMD has also revised the dates of onset and withdrawal dates of monsoon for several parts of the country based on data from 1960 to 2019.The previous dates were based on the data from 1901 to 1940.

However, the onset date for monsoon over Kerala, which is June 1, remains unchanged

In states like Maharashtra, Gujarat, Madhya Pradesh, Chhattisgarh, Telangana, Andhra Pradesh, Odisha, Jharkhand, Bihar and parts of Uttar Pradesh, monsoon will be delayed by three to seven days compared to the existing normal dates.

For Delhi, the new normal onset date for monsoon has been revised from June 23 to June 27, a delay of four days. Similarly, dates have been revised for Mumbai and Kolkata from June 10 to 11, and for Chennai from June 1 to 4.

However, over extreme northwest India, monsoonwill arrive a little earlier, on July 8, as compared to the existing date of July 15. The new date for monsoon withdrawal from south India is October 15.