A cyclonic circulation located on Thursday morning over the South-East Arabian Sea around 800 km from Kochi, 500-odd km from Kavaratti in Lakshadweep (1,036 km South-West of Mumbai, as per the US Joint Typhoon Warning Centre, JTWC) will set up an expected low-pressure area by tomorrow (Friday).

When declared, the ‘low’ will have the benefit some of the warmest tropical waters currently available globally (the Bay of Bengal is still warmer in some parts of the basin) underneath, which will help its intensification into a depression and further into the first pre-monsoon (May) cyclone this year in the Arabian Sea.

Warmer beyond threshold

Sea surface-temperatures in the East-Central Arabian Sea where the parent cyclonic circulation is currently located are at 31 degrees Celsius, way beyond the 27-28 degrees Celsius-threshold needed to sustain a storm. In contrast, the Central Bay of Bengal waters are warmer at 32 degrees Celsius.

India Meteorological Department (IMD) has said that the ‘low’ may concentrate into a depression over the Lakshadweep area and adjoining South-East and East-Central Arabian Sea by Saturday. It will likely move North-North-West and become a cyclone over East-Central Arabian Sea by Sunday.

Likely onward track

The would-be cyclone will continue to move North-North-West (which is almost parallel to the West Coast with face oriented towards the open sea) for ‘some more time with further intensification,’ the IMD said without specifying the track it could likely follow as an intensified system.

The JTWC cited global model forecasts which it says are in good agreement that the ‘low’ will consolidate and intensify as it tracks to the East over the next two days (closer to the Kerala and Karnataka coasts) and ranked the likelihood to ‘medium’ on a scale of low-medium-high.

Heavy rainfall warning

The IMD has warned of heavy to very heavy rainfall at a few places in Lakshadweep during Friday-Monday with isolated extremely heavy falls on the first two days; heavy to very heavy rainfall at a few places over Kerala and isolated places over Tamil Nadu, Coastal and South Interior Karnataka.

Fishermen are advised not to venture out to the South-East Arabian Sea and adjoining Maldives, Comorin and Lakshadweep area, Kerala coast from this (Thursday) morning; to the East-Central Arabian Sea and along and off Karnataka-Goa and Maharashtra and Goa coasts from tomorrow (Friday) night.