CHENNAI: Chennai, which woke up amid claps of thunder after a restless sleep on Tuesday, went to bed to relatively calm skies but with its fingers crossed. This was announced by the weather office Northeast monsoon had started after a well-developed low pressure area in the Bay of Bengal had intensified into a low pressure area. Several streets were submerged for a few hours in the morning, but there was no widespread flooding as water drained in most places as the rain showers eased in the afternoon.

The IMD has issued a red alert for Chennai, Kancheepuram, Tiruvallur and Chengalpet as these districts experienced heavy to very heavy rainfall (6 cm to 20 cm) overnight and extremely heavy rainfall (more than 21 cm) at one or two places ) can come.
Rainfall since Monday night was 12 cm in Nungambakkam and 10 cm in Meenambakkam in 35 hours ending at 7.30 pm on October 15.
The low pressure area, which was over the southwest Bay of Bengal, about 490 km east-southeast of Chennai, on Tuesday evening, is likely to cross north coastal Tamil Nadu and southern Andhra Pradesh between Puducherry and Nellore near Chennai early on Thursday.
“As the system crosses land, wind speeds of 35 km/h to 55 km/h may prevail. The rains were intermittent because clouds need to develop and the system needs to interact with the sea to continue developing. During northeast monsoon, rainfall intensity usually increases at night and early morning hours,” said S. Balachandran, deputy director general, IMD.
IMD has also issued an orange alert (6 cm to 20 cm) for 12 districts – Ranipet, Tiruvannamalai, Kallakurichi, Perambalur, Ariyalur, Mayiladuthurai, Nagapattinam, Thanjavur, Tiruvarur, Cuddalore, Villupuram and Vellore – as well as Puducherry and Karaikal.
Puzhal recorded 16 cm of rain in 11 hours
Six districts – Tirupattur, Krishnagiri, Dharmapuri, Salem, Trichy and Pudukottai – are on yellow alert (6 cm to 12 cm).
IMD said the northeast monsoon has started over Tamil Nadu, Puducherry, coastal Andhra Pradesh, Rayalaseema, southern interior Karnataka and Kerala, coinciding with the withdrawal of the southwest monsoon from the country.
In Chennai, coastal districts like Ennore recorded 10 cm in 24 hours ending at 8:30 am on October 14 and 13 cm in the 11 hours ending at 7:30 pm on October 15. Between 8:30 am and 7:30 pm on October 15, rainfall gauge at Puzhal recorded 16 cm, Good Will School, Villivakkam recorded 15 cm, Anna University 14 cm, Hindustan University 14 cm, YMCA Nandanam 12 cm, NIOT Pallikaranai 11 cm and Sathyabama University 7 cm rainfall.
Cuddalore recorded 3 cm, Tirupattur 3 cm and Tiruttani 2 cm. Many interior districts recorded less than 1 cm of rainfall.