Owing to the "well-marked low-pressure area" in the Bay of Bengal, the Indian Meteorological Department (IMD) has issued a Red Alert for very heavy to extremely heavy rainfall (up to 21 cm in 24 hours) for Tenkasi, Tirunelveli, and Thoothukudi districts in Tamil Nadu&nbsp;on Thursday, 12th December.&nbsp;

Chennai city and 16 districts of Tamil Nadu, the Union territory of Puducherry, have been issued an Orange alert for heavy to very heavy rainfall (12-20 cm), while 10 other districts have been issued a Yellow alert for heavy rain (7-11 cm).&nbsp;

In meteorology, a low-pressure area is associated with rainfall, stormy weather, rough sea conditions, and gusty winds.&nbsp;

Also read |&nbsp;<a href="https://www.wionews.com/india-news/imd-says-27-districts-across-tamil-nadu-on-alert-for-heavy-to-very-heavy-rainfall-783230">IMD says 27 districts across Tamil Nadu on alert for heavy to very heavy rainfall</a>

The weather system lay in the Palk Strait region, which is a narrow strip of ocean separating the southern Indian state of Tamil Nadu and the island nation of Sri Lanka.

The IMD maintains that the system is likely to move west-northwestwards towards the southern coast of Tamil Nadu, following which it will weaken into a 'low-pressure area' around Friday, 13th December. For Friday, a yellow alert for heavy rainfall has been issued for 12 districts spanning the western and southern regions of Tamil Nadu.&nbsp;

With winds forecast to be gusting at 55 kmph until Saturday, 14th December, fishermen have been advised to avoid venturing out along the Tamil Nadu Coast. Similar conditions are expected to prevail along parts of the Kerala coast as well, and a warning has been issued for fishermen.&nbsp;

Over the last 24 hours, a maximum of 18 cm of rainfall has been recorded in Kodiayakarai, Nagapattinam district, Tamil Nadu. Chennai city and adjoining regions have also witnessed around 10 cm of rainfall.&nbsp;

In light of the rainfall alert, five teams of the National Disaster Response Force (NDRF) are on standby for deployment, with 30 personnel in each team.

In addition to this, one team is pre-positioned at the Union Territory of Puducherry, while another is en route to Tiruvannamalai district, where a temple festival is to take place, amid the rainfall warning.&nbsp;

Owing to the "well-marked low-pressure area" in the Bay of Bengal, the Indian Meteorological Department (IMD) has issued a Red Alert for very heavy to extremely heavy rainfall (up to 21 cm in 24 hours) for Tenkasi, Tirunelveli, and Thoothukudi districts in Tamil Nadu on Thursday, 12th December.

Owing to the "well-marked low-pressure area" in the Bay of Bengal, the Indian Meteorological Department (IMD) has issued a Red Alert for very heavy to extremely heavy rainfall (up to 21 cm in 24 hours) for Tenkasi, Tirunelveli, and Thoothukudi districts in Tamil Nadu on Thursday, 12th December. Chennai city and 16 districts of Tamil Nadu, the Union territory of Puducherry, have been issued an Orange alert for heavy to very heavy rainfall (12-20 cm), while 10 other districts have been issued a Yellow alert for heavy rain (7-11 cm). In meteorology, a low-pressure area is associated with rainfall, stormy weather, rough sea conditions, and gusty winds. Also read | IMD says 27 districts across Tamil Nadu on alert for heavy to very heavy rainfall The weather system lay in the Palk Strait region, which is a narrow strip of ocean separating the southern Indian state of Tamil Nadu and the island nation of Sri Lanka. The IMD maintains that the system is likely to move west-northwestwards towards the southern coast of Tamil Nadu, following which it will weaken into a 'low-pressure area' around Friday, 13th December. For Friday, a yellow alert for heavy rainfall has been issued for 12 districts spanning the western and southern regions of Tamil Nadu. With winds forecast to be gusting at 55 kmph until Saturday, 14th December, fishermen have been advised to avoid venturing out along the Tamil Nadu Coast. Similar conditions are expected to prevail along parts of the Kerala coast as well, and a warning has been issued for fishermen. Over the last 24 hours, a maximum of 18 cm of rainfall has been recorded in Kodiayakarai, Nagapattinam district, Tamil Nadu. Chennai city and adjoining regions have also witnessed around 10 cm of rainfall. In light of the rainfall alert, five teams of the National Disaster Response Force (NDRF) are on standby for deployment, with 30 personnel in each team. In addition to this, one team is pre-positioned at the Union Territory of Puducherry, while another is en route to Tiruvannamalai district, where a temple festival is to take place, amid the rainfall warning.

Tamil Nadu: IMD red alert for 3 districts; 5 NDRF teams on standby

The evolving weather system off the Bay of Bengal is expected to move towards Sri Lanka and Tamil Nadu coasts during the next 24 hours, the Indian Meteorological Department (IMD) said on Wednesday (Dec 11). As the weather system moves north, northwestwards in the coming days, it is expected to bring heavy (7-11 cms) to very heavy rain (12-20 cms) in 28 districts of Tamil Nadu, and the adjoining Union Territory of Puducherry. In meteorology, a low-pressure area is associated with rainfall, stormy weather, rough sea conditions, and gusty winds.

Also read |&nbsp;<a href="https://www.wionews.com/india-news/weather-system-in-bay-of-bengal-rainfall-warning-for-17-districts-of-tamil-nadu-783032">Weather system in Bay of Bengal, rainfall warning for 17 districts of Tamil Nadu</a>

For Wednesday the IMD issued an orange alert for six districts of Tamil Nadu, warning of heavy to very heavy rain at isolated places over Cuddalore, Mayiladuthurai, Nagapattinam, Thanjavur, Tiruvarur, Pudukkottai districts. Similarly, a Yellow alert for heavy rain has been issued for Sivaganga, Ramanathapuram, Tiruchirappalli, Perambalur, Ariyalur, Kallakurichi, Villuppuram, Chengalpattu, Kancheepuram, Chennai, Tiruvallur districts of Tamil Nadu.

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Heavy <a href="https://twitter.com/hashtag/rainfall?src=hash&amp;ref_src=twsrc%5Etfw">#rainfall</a> warning for 27 districts across <a href="https://twitter.com/hashtag/TamilNadu?src=hash&amp;ref_src=twsrc%5Etfw">#TamilNadu</a> on 12th Dec, Thursday.. 
 
Orange alert issued for 4 districts, for very heavy rain (12-20cms) 
 
Yellow alert issued for 20+ districts, for heavy rain (7-11cms) <a href="https://twitter.com/hashtag/NEMonsoon?src=hash&amp;ref_src=twsrc%5Etfw">#NEMonsoon</a> <a href="https://twitter.com/hashtag/December?src=hash&amp;ref_src=twsrc%5Etfw">#December</a> <a href="https://twitter.com/hashtag/Chennai?src=hash&amp;ref_src=twsrc%5Etfw">#Chennai</a> <a href="https://twitter.com/hashtag/weather?src=hash&amp;ref_src=twsrc%5Etfw">#weather</a> <a href="https://t.co/GfGykusnVX">pic.twitter.com/GfGykusnVX</a>
— Sidharth.M.P (@sdhrthmp) <a href="https://twitter.com/sdhrthmp/status/1866781967532036256?ref_src=twsrc%5Etfw">December 11, 2024</a></blockquote>
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For Thursday&nbsp;(Dec 12), an orange alert for heavy to very heavy rain has been issued for isolated places over Ariyalur, Thanjavur, Tiruvarur and Pudukkottai districts of Tamilnadu.

Further, a yellow alert for heavy rain issued for isolated places over Chennai, Tiruvallur, Kancheepuram, Chengalpattu, Tiruvannamalai, Villupuram, Kallakurichi, Cuddalore, Perambalur, Tiruchirappalli, Sivaganga, Ramanathapuram, Mayiladuthurai, Nagapattinam, Coimbatore, Tiruppur, Karur, Theni, Dindigul, Madurai, Virudhunagar, Tenkasi, Thoothukudi districts of Tamilnadu, and the Union Territory of Puducherry.

As per the IMD, the impact of this weather system could continue to bring rainfall across parts of Tamil Nadu, over the next five days.

Owing to rough sea conditions and gusty winds, the IMD has advised fishermen against fishing along the Tamil Nadu coast.

This weather system and the rainfall alert came barely 10 days after the impact of Cyclone Fengal, which claimed 19 lives across Sri Lanka and Southern India. The October-December period is the Northeast monsoon season which brings rains to India's eastern coastal states such as Tamil Nadu, Andhra Pradesh, and Odisha.

The evolving weather system off the Bay of Bengal is expected to move towards Sri Lanka and Tamil Nadu coasts during the next 24 hours, the Indian Meteorological Department (IMD) said on Wednesday (Dec 11).

The evolving weather system off the Bay of Bengal is expected to move towards Sri Lanka and Tamil Nadu coasts during the next 24 hours, the Indian Meteorological Department (IMD) said on Wednesday (Dec 11). As the weather system moves north, northwestwards in the coming days, it is expected to bring heavy (7-11 cms) to very heavy rain (12-20 cms) in 28 districts of Tamil Nadu, and the adjoining Union Territory of Puducherry. In meteorology, a low-pressure area is associated with rainfall, stormy weather, rough sea conditions, and gusty winds. Also read | Weather system in Bay of Bengal, rainfall warning for 17 districts of Tamil Nadu For Wednesday the IMD issued an orange alert for six districts of Tamil Nadu, warning of heavy to very heavy rain at isolated places over Cuddalore, Mayiladuthurai, Nagapattinam, Thanjavur, Tiruvarur, Pudukkottai districts. Similarly, a Yellow alert for heavy rain has been issued for Sivaganga, Ramanathapuram, Tiruchirappalli, Perambalur, Ariyalur, Kallakurichi, Villuppuram, Chengalpattu, Kancheepuram, Chennai, Tiruvallur districts of Tamil Nadu. Heavy #rainfall warning for 27 districts across #TamilNadu on 12th Dec, Thursday.. Orange alert issued for 4 districts, for very heavy rain (12-20cms) Yellow alert issued for 20+ districts, for heavy rain (7-11cms) #NEMonsoon #December #Chennai #weather pic.twitter.com/GfGykusnVX — Sidharth.M.P (@sdhrthmp) December 11, 2024 × For Thursday (Dec 12), an orange alert for heavy to very heavy rain has been issued for isolated places over Ariyalur, Thanjavur, Tiruvarur and Pudukkottai districts of Tamilnadu. Further, a yellow alert for heavy rain issued for isolated places over Chennai, Tiruvallur, Kancheepuram, Chengalpattu, Tiruvannamalai, Villupuram, Kallakurichi, Cuddalore, Perambalur, Tiruchirappalli, Sivaganga, Ramanathapuram, Mayiladuthurai, Nagapattinam, Coimbatore, Tiruppur, Karur, Theni, Dindigul, Madurai, Virudhunagar, Tenkasi, Thoothukudi districts of Tamilnadu, and the Union Territory of Puducherry. As per the IMD, the impact of this weather system could continue to bring rainfall across parts of Tamil Nadu, over the next five days. Owing to rough sea conditions and gusty winds, the IMD has advised fishermen against fishing along the Tamil Nadu coast. This weather system and the rainfall alert came barely 10 days after the impact of Cyclone Fengal, which claimed 19 lives across Sri Lanka and Southern India. The October-December period is the Northeast monsoon season which brings rains to India's eastern coastal states such as Tamil Nadu, Andhra Pradesh, and Odisha.

IMD says 27 districts across Tamil Nadu on alert for heavy to very heavy rainfall

According to the observations by the Indian Meteorological Department(IMD), a low-pressure area has formed over the Southeast Bay of Bengal, as of 5:30 am IST, Monday (Oct 14).

Over the next 48 hours, it is likely to become a well-marked low-pressure area and move west-northwestwards towards North Tamil Nadu and South Andhra Pradesh coasts, which puts Chennai city and adjoining districts on track for rainfall.&nbsp;

In Meteorology, a low-pressure area is a region where the atmospheric pressure is lower than the surrounding areas. Low-pressure systems often bring overcast skies, showers, or storms. Strong low-pressure systems can intensify into larger weather events like tropical storms, cyclones, or hurricanes.&nbsp;

Also read:&nbsp;<a href="https://www.wionews.com/india-news/water-supply-to-be-affected-in-noida-and-ghaziabad-till-nov-2-767307">Water supply to be affected in Noida and Ghaziabad till Nov 2</a>

Owing to this evolving weather system, Chennai and adjoining districts are likely to receive heavy to very heavy rainfall on Monday and Tuesday. However, there is a forecast of extremely heavy rainfall in Chennai and adjoining districts for Wednesday, on Thursday this could subside to heavy rainfall over the region.&nbsp;

As per the IMD's classification, heavy rainfall amounts to 6.4-11.5 cm&nbsp;of downpour in 24 hours, whereas very heavy rainfall amounts to 11.5 cm&nbsp;to 20.4 cm in 24 hours. In case of extremely heavy rainfall, it is more than 20.4 cm&nbsp;in 24 hours.&nbsp;

<h2>NDRF teams on alert</h2>

Ten teams of the National Disaster Response Force(NDRF), comprising a total of 300 personnel are on standby at Arakkonam, near Chennai. In addition to this, one team has already been pre-positioned in Chennai city for any immediate requirements.

NDRF teams are working in close coordination with the State authorities, to render assistance at the required time and place.

Each of these NDRF teams is prepared with rubber boats, tree-cutting chainsaws, communications equipment, ropes and harnesses, first aid kids etc.

According to the observations by the Indian Meteorological Department(IMD), a low-pressure area has formed over the Southeast Bay of Bengal, as of 5:30 am IST, Monday (Oct 14).

According to the observations by the Indian Meteorological Department(IMD), a low-pressure area has formed over the Southeast Bay of Bengal, as of 5:30 am IST, Monday (Oct 14). Over the next 48 hours, it is likely to become a well-marked low-pressure area and move west-northwestwards towards North Tamil Nadu and South Andhra Pradesh coasts, which puts Chennai city and adjoining districts on track for rainfall. In Meteorology, a low-pressure area is a region where the atmospheric pressure is lower than the surrounding areas. Low-pressure systems often bring overcast skies, showers, or storms. Strong low-pressure systems can intensify into larger weather events like tropical storms, cyclones, or hurricanes. Also read: Water supply to be affected in Noida and Ghaziabad till Nov 2 Owing to this evolving weather system, Chennai and adjoining districts are likely to receive heavy to very heavy rainfall on Monday and Tuesday. However, there is a forecast of extremely heavy rainfall in Chennai and adjoining districts for Wednesday, on Thursday this could subside to heavy rainfall over the region. As per the IMD's classification, heavy rainfall amounts to 6.4-11.5 cm of downpour in 24 hours, whereas very heavy rainfall amounts to 11.5 cm to 20.4 cm in 24 hours. In case of extremely heavy rainfall, it is more than 20.4 cm in 24 hours. NDRF teams on alert Ten teams of the National Disaster Response Force(NDRF), comprising a total of 300 personnel are on standby at Arakkonam, near Chennai. In addition to this, one team has already been pre-positioned in Chennai city for any immediate requirements. NDRF teams are working in close coordination with the State authorities, to render assistance at the required time and place. Each of these NDRF teams is prepared with rubber boats, tree-cutting chainsaws, communications equipment, ropes and harnesses, first aid kids etc.

Storm brewing in Bay of Bengal, extremely heavy rainfall warning for Chennai