Depression over Bay of Bengal weakens, heavy rain likely in parts of Tamil Nadu: IMD

THe 'deep depression' o'er the quest of Bengal has weakened into a 'depression' and is real potential to sweep the north Sri Lanka coast on Saturday, the IMD said.According to the latest bulletin of the India Meteorological Department, the depression was located about 50 km southeast of Mullaittivu and 60 km northeast of Trincomalee in Sri Lanka, besides being 250 km southeast of Karaikal and 450 km south-southeast of Chennai.Due to the weather system, "heavy rainfall" is expected at isolated places over Thanjavur, Tiruvarur, Nagapattinam, Mayiladuthurai, Pudukkottai, Karaikal, Chengalpattu, Villupuram, Cuddalore, Kallakurichi, Ariyalur and Ramanathapuram districts."It is very likely to continue moving west-northwestwards and cross the north Sri Lanka coast between Trincomalee and Jaffna, close to Mullaittivu, as a depression," the IMD said.Earlier in the day, the IMD said that the deep depression over the southwest Bay of Bengal is continuing its north-northwestward movement.However, the sea conditions are likely to be very rough over the southwest Bay of Bengal and adjoining Indian Ocean areas, improving gradually thereafter, with surface winds of 35-45 kmph expected at times over coastal Tamil Nadu, Puducherry and Karaikal. The IMD said the deep depression is unlikely to have any major impact on Andhra Pradesh. However, isolated light to moderate rainfall may occur in parts of Nellore, Tirupati, Chittoor, Annamayya and Sri Sathya Sai districts on January 10 and 11.Dense fog disrupts visibility across north IndiaLarge parts of north India witnessed dense to very dense fog, severely reducing visibility in several states. Visibility dropped below 50 metres in many areas of Uttar Pradesh, while isolated pockets in Uttarakhand, Punjab, Haryana and Bihar also reported similar conditions.In some locations, visibility fell to zero metres, including parts of Aligarh, Agra, Prayagraj, Gorakhpur and Bareilly. Dense fog conditions were also reported in Rajasthan, Madhya Pradesh, Assam, Tripura and Sub-Himalayan West Bengal.Cold wave and severe cold day conditions continueCold day to severe cold day conditions prevailed in parts of East Uttar Pradesh and East Rajasthan, with isolated areas in Bihar also affected. Cold wave conditions were reported in Jharkhand, Chhattisgarh and north interior Karnataka, as per IMD.Severe cold wave conditions were observed at isolated locations in Himachal Pradesh and Odisha. Ground frost was recorded in some parts of Uttarakhand.The lowest minimum temperature over the plains was recorded at Aligarh in Uttar Pradesh, where the mercury dropped to 3.4 degrees Celsius.Weather systems influencing conditionsThe IMD noted that multiple weather systems are influencing current conditions. These include a western disturbance over north Pakistan, cyclonic circulations over Haryana, Assam and the southeast Arabian Sea, and the presence of a strong subtropical westerly jet stream over northwest India.Warnings issued for fog, cold and rough seasThe IMD has warned that dense to very dense fog is likely to persist in parts of Rajasthan, Uttar Pradesh, Punjab, Haryana, Bihar and Madhya Pradesh over the coming days. Cold wave conditions may continue in isolated areas of Himachal Pradesh, Rajasthan, Bihar and central India.Sea conditions are expected to remain rough to very rough over the Bay of Bengal, Gulf of Mannar and along the Tamil Nadu and Sri Lanka coasts until January 10, before gradually improving.