The southwest monsoon is likely to hit Kerala on June 1, due to a cyclonic circulation over the Bay of Bengal, the Indian Meteorological Department (IMD) said on Thursday.
The IMD, in its onset date forecast on May 15, had said the monsoon is likely to hit the southern state on June 5, four days after its normal arrival.
The normal onset of monsoon over Kerala is June 1.
However, a cyclonic circulation over the Bay of Bengal is likely to help in the faster progress of the monsoon.
"A low pressure area is likely to form over southeast and adjoining east central Arabian Sea during May 31 to June 4. In view of this, conditions are very likely to become favourable from June 1 for onset of southwest monsoon over Kerala," the IMD said.
A low pressure area is the first stage of any cyclone. It is not necessary that every low pressure intensifies into a cyclonic circulation.
According to the IMD, the country is likely to receive normal monsoon this year.
A low pressure area has also formed over west-central Arabian Sea. It is very likely to concentrate into a depression over the same region during the next 48 hours, IMD said on Thursday.
It is likely to move northwestwards towards south Oman and east Yemen coast during the next three days, the IMD added.
Under the influence of this weather system, heavy rainfall is likely over parts of south peninsular India during May 28-31, with isolated heavy to very heavy rainfall over Kerala and Lakshadweep during May 30-31.
The Kerala government has warned fishermen not to venture out to sea from Thursday midnight and prohibited fishing activities in view of the possible formation of the low pressure area over Southeast and adjoining Arabian Sea.
"Fishing activities have been completely prohibited since midnight tonight (Thursday) on the Kerala coast and South East parts of the Arabian sea. Those who have already left for the deep sea, should return to the coast as early as possible," Chief Minister Pinarayi Vijayan told reporters in Thiruvananthapuram.
Many parts of Kerala have been receiving rains since the past few days.
The chief amounts of rainfall are: Cherthala and Mancompu (both in Alappuzha district) 5 cm each, Thodupuzha (Idukki district) and Chalakudy (Thrissur district) 3 cm each.
"We can expect more than the normal this year too. In the next five days, the rains are likely to continue as per the IMD forecast," Pinarayi said.
Kerala had received unprecedented rains during the previous two consecutive monsoons, causing massive devastation and claiming hundreds of lives, besides leaving many homeless.
Meanwhile, there was no large change in maximum temperature in all the districts of Kerala during the past 24 hours.
However, it was appreciably above normal in Alappuzha, Kozhikode and Palakkad districts, above normal in Malappuram, Kannur and Kottayam districts, and remained normal elsewhere over the state.
Palakkad recorded the highest maximum temperature of 37 degree Celsius.