Weather watch. It’s a deep depression now over Bay, a spin away from being cyclone 

Tuesday evening’s depression over the South-East Bay of Bengal intensified into a deep depression early on Wednesday morning, only a spin away from being classified as a cyclone, and was located 570 km East of Trincomalee and 710 km East-Southeast of Jaffna (both Sri Lanka); 770 km East-South-East of Karaikal; and 830 km South-East of Chennai. 

It is expected to be called a cyclone (to be called ‘Mandous’) by Wednesday evening, and will retain its status until 5.30 pm on Friday, India Meteorological Department (IMD) said. The causative depression lay closest to the Sri Lankan coast on Wednesday morning, but the projected track will guide it towards the North Tamil Nadu coast around Chennai by Friday evening. 

Rain forecast for Tamil Nadu

On Thursday, light to moderate rainfall is expected at most places over Coastal Tamil Nadu, Puducherry and Karaikal as well as adjoining areas of South Coastal Andhra Pradesh with heavy to very heavy falls at isolated places. On Friday, it will be light to moderate at most places with heavy to very heavy rainfall at a few places and extremely heavy at isolated places and isolated heavy to very heavy over North Interior Tamil Nadu and adjoining Rayalaseema. It may reduce to light to moderate rainfall at many places with heavy to very heavy rainfall at isolated places over North Tamil Nadu and Rayalaseema and South Andhra Pradesh on Saturday. 

Cyclone may weaken 

From Friday evening, the cyclone may start to weaken before crossing the coast to the North of Chennai, based on current predictions on track of movement and intensity. After being classified as one on Wednesday, the cyclone will continue to move west-northwestwards for at least two days, towards the North Tamil Nadu-Puducherry and South Andhra Pradesh coasts. 

Squally winds with speed reaching 50-60 kmph gusting to 70 kmph may prevail over the South-East Bay until Thursday and reduce to 40-45 kmph gusting to 55 kmph on Friday. Similar conditions are expected closer to the coast over the South-West Bay with wind speeds of 50-60 kmph gusting to 70 kmph. They would increase 60-70 kmph gusting to 80 kmph from Wednesday evening. 

High winds outlook

By Thursday morning, they would increase to gale wind speeds reaching 70-80 kmph gusting to 90 kmph over the same region and to 80-90 kmph gusting to 100 kmph into the evening and Friday morning. At this level, the winds would have peaked in terms of speed and intensity, and may start winding down gradually to coincide with the likely landfall of the cyclone.

As for the coast, wind speeds may reach 40-50 kmph gusting to 60 kmph from Thursday morning along and off Tamil Nadu, Puducherry, South Andhra Pradesh and North Sri Lanka. They would scale up to 50-60 kmph gusting to 70 kmph from the same evening and 70-80 kmph gusting to 90 kmph from Friday evening to Saturday when they will likely start weakening. 

Rough sea conditions

Wind speeds will reduce gradually to 50-60 kmph gusting to 70 kmph by Saturday afternoon and further to 40-50 kmph gusting to 60 kmph (back to depression strength) by Saturday night. Squally winds with speeds reaching 40-50 kmph gusting to 60 kmph may prevail over the Gulf of Mannar from Thursday evening becoming 50-60 kmph gusting to 70 kmph from Friday evening to Saturday morning. It is likely to reduce gradually thereafter, signalling the landfall of the cyclone. 

Warning to fishermen

The sea condition will be ‘rough to very rough’ (wave heights of 8-13 ft) over the South-East Bay on Wednesday, and stay as such over South-West and adjoining areas of West-Central Bay until the same evening. It will become ‘very rough to high’ (13-20 ft) thereafter till Saturday morning, before improving. Along the coast, the sea condition will be ‘rough to very rough’ along and off the South Andhra Pradesh, Tamil Nadu, Puducherry and Sri Lanka on Wednesday, Thursday and Saturday and ‘high’ (20-30ft) on Friday. Fishermen are advised not to venture into these areas and those out at sea should return to the coast or move to safe area.

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