Cyclonic storm Ditwah heads towards Tamil Nadu, Puducherry; red alerts issued

Cyclonic storm 'Ditwah', formed from a deep depression near the Sri Lanka coast, has begun moving towards the north Tamil Nadu, Puducherry and south Andhra coasts, Regional Meteorological Centre Director B Amudha said in Chennai on Thursday.

Strong winds, heavy rain and dangerous sea conditions are expected over the next few days, she added.

Meanwhile, Tamil Nadu State Disaster Management Authority met under the leadership of Chief Minister M K Stalin to review special initiatives undertaken for disaster management.

"It (Ditwah) is currently being treated as a cyclonic storm. Forecasts do not, at present, upgrade it to a severe cyclone," the RMC chief said.

However, the RMC has issued a red alert in some Cauvery Delta districts and an orange alert in five districts -- Chennai, Tiruvallur, Kancheepuram, Ranipet and Chengalpattu for November 20 and 30.

Thanjavur, Tiruvarur, Nagapattinam and Mayiladuthurai are the delta districts that have been issued a red alert.

A red alert indicates an extremely heavy rain of over 20 cm in 24 hours, while an orange alert means very heavy rain of 11 cm to 20 cm.

The name, 'Ditwah', referring to the lagoon, was suggested by Yemen, the RMC chief said. It is likely named after Detwah Lagoon, a large, saline lagoon on the northwest coast of the island of Socotra in Yemen.

Briefing reporters in the RMC's office in Chennai, Amudha said gale winds near the storm centre could reach 60–80 kmph with gusts up to 90 kmph, while outer bands are likely to experience winds of 35–45 kmph, gusting to 55 kmph.

"Similar squally winds of 35–45 kmph, with gusts up to 55 kmph, are also expected over parts of the Arabian Sea adjoining Kerala, Lakshadweep and Maldives," she added.

Fishermen, especially those already in the deep sea, have been advised to completely avoid the south, central, southwest and southeast Bay of Bengal for the next five days, she said.

In the 24 hours preceding the briefing, isolated rainfall was reported in Tamil Nadu with Thangachimadam recording about 3 cm, while Puducherry and Karaikal remained largely dry, Amudha said.

Reviewing the northeast monsoon, the official said Tamil Nadu has so far received around 35 cm of rain against a normal of 34 cm from October 1, translating to roughly two per cent above normal for the season.

"However, Chennai’s seasonal rainfall remains around 31 per cent below normal, and the storm could significantly improve the deficit if it brings widespread showers over the next few days," she said.

Possibility of landfall could be predicted only when the track and speed evolve, she added.

Following the warning by the RMC that very heavy rain (red alert) may occur in specific districts on November 29 and 30, CM Stalin has requested all government departments to coordinate among themselves and serve the people, according to an official release.

The functioning of automated weather instruments installed for real-time disaster monitoring, Chennai Real-Time Flood Forecasting System, the Integrated Flood Monitoring Center of the Tamil Nadu Disaster Risk Reduction System, the upgraded State Emergency Operations Center, the TN Alert app for the public and the TN Smart 2.0 web portal for government officials were also discussed in the meeting, the release added.