Wednesday’s low-pressure area over the South-West Bay of Bengal off Sri Lanka coast has persisted on Thursday and is likely to become ‘more marked’ (intensify) by Friday, according to India Meteorological Department (IMD). The ‘low’ is expected to move towards the Tamilnadu-Puducherry coasts till Saturday morning. After crossing the coast, it would move to the West-North-West across Tamil Nadu-Puducherry and later adjoining Kerala during Saturday-Sunday, the IMD added. 

May spawn successor 

According to IMD’s numerical model projections, the system will graze the northern parts of Sri Lanka before entering Tamil Nadu and move to penetrate Kerala. From here, it would step out into the South-East Arabian Sea and undergo some strengthening. Importantly, it would leave a trail of moisture back over the Bay of Bengal and spark the formation of stronger weather system by November 18. 

US agency forecast 

The US National Centres for Environmental Prediction points to the possibility of heavy to very heavy rainfall for entire Coastal Tamil Nadu and adjoining South Coastal Andhra Pradesh during the ongoing week ending on November 18 (Friday next). The subsequent week leading into the month-end might see the heavier rains fan out to parts of North Coastal Tamil Nadu (around Chennai) and adjoining South Coastal Andhra Pradesh, Telangana, North Interior Karnataka, and parts of West Maharashtra. 

Heavy to very heavy rain

Meanwhile, the IMD said the existing ‘low’ will bring fairly widespread to widespread rainfall with isolated heavy to very heavy rainfall over Tamil Nadu, Puducherry, Karaikal, Rayalaseemam, and South Coastal Andhra Pradesh for three days from Friday and isolated heavy rainfall over Kerala and Mahe from Friday to Monday in line with the track of the weather system. Isolated extremely heavy rainfall is also likely over North Coastal Tamil Nadu (including over Chennai), Puducherry, and Karaikal on Friday; and over North Tamil Nadu, Puducherry, and Karaikal on Saturday. 

Warning to fishermen 

The intensified ‘low’ will bring squally weather with wind speeds of 40-45 kmph gusting to 55 kmph (depression-strength) over South-West and adjoining West-Central Bay (off the Tamil Nadu and Andhra Pradesh coasts); along and off the South Andhra Pradesh-Tamil Nadu-Puducherry and Sri Lanka coasts; the Gulf of Mannar and adjoining Comorin area during next three days. Fishermen are advised not to venture in to these areas during the same period. An extended IMD forecast said fairly widespread light to moderate rainfall is likely over many parts of the South Peninsula and the Islands in the Bay and the Arabian Sea in an apparent reference to formation of the second ‘low.’