The depression over the southwest Bay of Bengal will intensify into a cyclonic storm on December 3 resulting in heavy to very heavy rains in the northern coastal districts of Tamil Nadu and interior parts, too, the India Meteorological Department said on Saturday.

It would reach the west central Bay of Bengal off south Andhra Pradesh and adjoining north Tamil Nadu coasts by December 4 morning. Thereafter, it would move nearly northwards, almost parallel and close to the south Andhra Pradesh coast, and cross the south Andhra Pradesh coast between Nellore and Machilipatnam during the December 5 forenoon, the IMD said in its latest bulletin.

The cyclonic activity would lead the winds to blow at a speed of 80-90 kmph gusting to 100 kmph.

According to S Balachandran, deputy director general of the Regional Meteorological Centre, here, heavy to very heavy rains are likely to occur over Pudukkottai, Thanjavur, Tiruvarur, Nagapattinam, Tiruvallur, Chennai, Kancheepuram, Ranipet, Chengalpattu, Villupuram and Cuddalore districts.

Squally wind prevailing over the southwest Bay of Bengal is likely to become gales reaching 60-70 kmph gusting to 80 kmph from December 2 night to December 4. Thereafter, it would gradually decrease.

From October 1 till date, the region recorded 34 cm rainfall against the normal 36 cm during the North East Monsoon period, so far, Balachandran said. Chennai alone recorded 62 cm against the normal rainfall of 67 cm during this period.

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