Rain, thunderstorms likely across TN; northern districts under heavy rain warning

CHENNAI: The southwest monsoon continues to be vigorous over Tamil Nadu, with widespread rainfall activity expected in the coming days.

According to the Regional Meteorological Centre (RMC), many places in the northern districts and a few pockets elsewhere are likely to receive showers.

For Tamil Nadu, Puducherry and Karaikal, the forecast for September 20 and 21 indicates light to moderate rain at a few places in the north and at isolated places in the south, accompanied by thunderstorms, lightning and gusty winds reaching 30–40 kmph. From September 22-25, light to moderate rain is likely at isolated places across the region.

A heavy rainfall warning has been issued for Tirupattur, Vellore, Ranipet, Tiruvallur, Kancheepuram and Tiruvannamalai, where isolated heavy spells are expected. Thunderstorm warnings remain in place for TN, Puducherry and Karaikal up to September 21.

In Chennai, the sky will be partly cloudy with one or two spells of moderate rain, accompanied by thunder and lightning in some areas. The maximum temperature is likely to be around 32-33°C and the minimum around 25-26°C.

Maximum temperatures are expected to remain near normal in most parts, though some areas may see a rise of 1-2°C. A few pockets could record temperatures two to three degrees above normal. Palayamkottai is likely to remain one of the hotter spots with a maximum around 38.5°C, while Karur Paramathi is expected to record the lowest minimum at about 21°C in the plains.

The rainfall is being driven by an upper air cyclonic circulation lying over the North Andaman Sea and adjoining Myanmar coast, extending up to 3.1 km above mean sea level.