Today (27.11.2021)
Thunderstorm with scattered heavy to isolated very heavy rain is likely to occur over Tirunelveli, Thoothukudi, Thenkasi, Chennai, Tiruvallur, Kancheepuram and Chengalpattu districts of Tamilnadu.
Thunderstorm with scattered heavy rain is likely to occur over Kanyakumari, Ramanathapuram, Tiruchirapalli, Karur, Coimbatore and Nilgiris districts of Tamilnadu.
Thunderstorm with moderate rain is likely to occur at most places over rest Tamilnadu, Puducherry and Karaikal area.

Tomorrow (28.11.2021)
Thunderstorm with scattered heavy to isolated very heavy rain is likely to occur over Chennai, Tiruvallur, Kancheepuram, Chengalpattu and Villupuram districts of Tamilnadu.
Thunderstorm with scattered heavy rain is likely to occur over Ariyalur,Pudukottai, Ramanathapuram, Tiruchirapalli, Karur, Madurai and delta districts of Tamilnadu and Karaikal area.
Thunderstorm with moderate rain is likely to occur at most places over rest Tamilnadu and Puducherry.

HEAVY RAINFALL WARNING:

Today (27.11.2021): Scattered heavy to isolated very heavy rain is likely to occur over Tirunelveli, Thoothukudi,Thenkasi, Chennai, Tiruvallur, Kancheepuram and Chengalpattu districts of Tamilnadu.
Scattered heavy rain is also likely to occur over Kanyakumari, Ramanathapuram, Tiruchirapalli, Karur, Coimbatore and Nilgiris districts of Tamilnadu.

Tomorrow (28.11.2021): Scattered heavy to isolated very heavy rain is likely to occur over Chennai, Tiruvallur,Kancheepuram, Chengalpattu and Villupuram districts of Tamilnadu.
Scattered heavy rain is also likely to occur over Ariyalur, Pudukottai, Ramanathapuram, Tiruchirapalli, Karur, Madurai and delta districts of Tamilnadu and Karaikal area.

THUNDERSTORM WARNING:
Thunderstorm with lightning is likely to occur at isolated places over Tamil Nadu.

LOCAL FORECAST FOR CHENNAI CITY AND NEIGHBOURHOOD:
For next 24 HRS: Thunderstorm with heavy to very heavy rain is likely to occur.

Reference:
http://imdchennai.gov.in/tn_fc.pdf
http://www.imdchennai.gov.in/hrw_district.htm