Key Points

The alert comes as Tamil Nadu begins to witness the revival of the southwest monsoon after a prolonged spell of intense summer heat.

An orange alert is issued when heavy rainfall is anticipated, typically exceeding 115.6 mm and up to 204.4 mm within 24 hours, and indicates a heightened risk of flooding.

After days of soaring temperatures, parts of the north interior Tamil Nadu and Chennai have received welcome relief with sudden afternoon showers. Localities such as Mylapore, Chintadripet, Anna Nagar, Adyar, and Chepauk experienced sharp rainfall from around 2.30 p.m. on Monday, leading to a dramatic drop in temperature. The day’s maximum fell from 38 degrees Celsius to 30 degrees by 4.00 p.m., aided by overcast skies and cool winds.

However, the rain also caused brief traffic disruptions, with waterlogging reported along arterial stretches, including Jawaharlal Nehru Salai.

Weather stations at Nungambakkam and Puzhal recorded 2 cm of rainfall by 5.30 p.m. on Monday. The RMC has forecast continued wet weather across Tamil Nadu and Puducherry for the rest of the week.

Thunderstorms accompanied by gusty winds reaching speeds of 30-40 kmph are expected in isolated pockets.

On Tuesday, isolated heavy rainfall is likely in seven districts, including Erode, Vellore, and Ranipet. The intensity of rain is projected to increase from Wednesday, with 15 districts -- including the delta region, interior Tamil Nadu, and the Western Ghats -- likely to experience heavier downpours.

B. Amudha, Head (Additional In-charge) of RMC Chennai, attributed the current weather pattern to the formation of an east-west trough in the upper atmosphere. She said the trough is facilitating the monsoonal flow and that rainfall would likely intensify in northern districts first before shifting towards the Ghat regions.

The prevailing weather system is expected to lower daytime temperatures by around 2 degrees across several parts of the state. The official also confirmed that the southwest monsoon is gradually reviving over Tamil Nadu, in line with similar activity recently seen in Karnataka. Chennai and its suburbs can expect light to moderate showers to continue through Tuesday, providing ongoing relief from the oppressive summer heat.

- IANS