This monsoon’s first cyclone, waiting in the wings, may trigger heavy rains over north T.N. from tomorrow

A low pressure area in the Bay of Bengal is likely to turn into a depression by Tuesday evening; 13 districts including Chennai may receive heavy rainfall between Wednesday and Friday, as per forecasts

This Northeast monsoon’s first cyclonic storm, brewing over the Bay of Bengal, is likely to reach close to the coasts north Tamil Nadu, Puducherry and South Andhra Pradesh by Thursday morning, December 8. This may trigger a spell of heavy rainfall over the northern parts of the State between Wednesday and Friday, December 7 and 9.

According to the Regional Meteorological Centre, Chennai, the well-marked low pressure area over the southwest Bay of Bengal is likely to gain strength, turning into a depression by Tuesday evening. The weather system will gradually intensify into a cyclonic storm and reach the southwest Bay of Bengal, near the north Tamil Nadu coast, by Thursday morning.

Heavy rains may gradually increase on Wednesday and cover more districts on Thursday and Friday. While fairly widespread rains are likely over the coastal region on Wednesday, rains may be heavy in one or two places in Cuddalore, Mayiladuthurai, Thanjavur, Thiruvarur, Nagapattinam and Pudukottai districts.

A Nowcast bulletin released at 10 a.m. on Tuesday predicted light to moderate rains in one or two weather stations over Krishnagiri, Salem, Erode, Tiruppur, Karur and Dharmapuri during the next 3 hours

As the storm moves closer to T.N. coast on Thursday, the intensity of rains is expected to be heavy to very heavy over 13 districts: Chennai, Tiruvallur, Kancheepuram, Chengalpattu, Villupuram, Kallakurichi, Cuddalore, Ariyalur, Perambalur, Mayiladuthurai, Thanjavur, Thiruvarur and Nagapattinam, and the Puducherry, Karaikal Union Territory area. One or two places in these districts may have extremely heavy rains too.

Eight districts, including Vellore, Tiruchi and Sivaganga, may experience isolated heavy rains on Thursday.

Widespread rains may continue on Friday too, over the State. For the second consecutive day (Thursday and Friday), Chennai and its neighbouring districts may experience intense rainfall. Eight other districts, including Salem, Ranipet and Dharmapuri may receive heavy or very heavy rainfall.