The monsoon has set foot in Kerala, the Met office said on Thursday.
The season’s onset in the Indian mainland is a week behind schedule. In Bengal, it is not expected before “at least four to five days”, said a Met official.
“Southwest monsoon has advanced into remaining parts of south Arabian Sea and some parts of central Arabian Sea, entire Lakshadweep area, most parts of Kerala, most parts of south Tamil Nadu, remaining parts of Comorin area, Gulf of Mannar and some more parts of southwest, central and northeast Bay of Bengal. Thus, Southwest monsoon has set foot over Kerala today, 8th June, 2023, against the normal date of 1st June,” said a Met release.
The statement said conditions are favourable for further advance of the southwest monsoon “into some more parts of central Arabian Sea, remaining parts of Kerala, some more parts of Tamil Nadu, some parts of Karnataka and some more parts of southwest, central and northeast Bay of Bengal and some parts of the northeastern states” in the next 48 hours.
Met officials in Kolkata said the expected date of arrival of the rains in Bengal will be clearer after the monsoon reaches the Northeast.
Usually, the monsoon arrived in Bengal four to five days after its arrival in the Northeast.
The usual onset date for north Bengal is June 5 and for south Bengal is June 8.
The weather department studies various factors such as amount and distribution of rainfall and wind flow and moisture content in the air to decide whether to declare the onset of the monsoon in a particular area.
“A strong system on the Bay of Bengal can propel the monsoon into Bengal earlier than the usual time it takes to arrive via the Northeast. But as of now, there is no possibility of such a system,” said a Met official.
There is a cyclonic circulation over the east-central Bay. But the system is expected to move inland, towards the Northeast, over the next 48 hours.
The maximum temperature in Kolkata on Thursday was 36.1 degrees Celsius, down a couple of notches from the day before. But the dip was offset by a rise in the minimum relative humidity, a marker of the moisture content in theair during the driest part of the day.
The minimum relative humidity was around 50 per cent on Thursday, compared with 39 per cent on Wednesday.
The rise was attributed to breakaway clouds from Bangladesh formed under theinfluence of the cyclonic circulation over the east-central Bay.
“But the clouds were weak. Whatever moisture is present is in the lower levels of the atmosphere. The upper level is still dry,” said G.K. Das, director, IMD, Kolkata.
The clouds are expected to be gone by Friday and the Celsius is likely to rise again, he said.