THIRUVANANTHAPURAM: Following the formation of low pressure area over Arbian sea, Yellow alert was declared in Thiruvananthapuram, Kollam, Pathanamthitta, Alappuzha, Kottayam, Ernakulam, Idukki, Malappuram and Kannur on Monday.

Currently, there are two low pressure area over Arabian sea near Kerala shores – one over the western shores and the other between Kerala and Lakshadweep.

The low pressure has gained strength over the last 48 hours and is likely to turn into Nipah cyclone by Tuesday. The India Met department is expected to officially announce the onset of monsoon in Kerala at a press conference to be held at 2pm on Monday.

As there are chances for strong wind at 45 to 55 km/hr speed, fishermen have been warned against going for trawling till June 4.

Meanwhile, the Met department has informed that the monsoon will reach Kerala on June itself. It has forecast heavy rain accompanied by thunder all over Kerala. The sea can also be rough in certain places.