Chennai, Nov 27 (IANS) The weather system brewing over the southwest Bay of Bengal and the adjoining Sri Lanka coast intensified into a deep depression on Thursday, with meteorologists warning that it will strengthen into a cyclonic storm by Thursday evening.

According to the Regional Meteorological Centre (RMC), the system is expected to move northwestwards across the southwest Bay and the Sri Lankan coastline toward north Tamil Nadu, Puducherry and adjoining south Andhra Pradesh coast by Saturday.

Once the system reaches cyclonic strength, it will be named Cyclone Ditwah, a name contributed by Yemen in the list of tropical cyclone names finalised by member nations of the World Meteorological Organisation (WMO) and the UN Economic and Social Commission for Asia and the Pacific (UN-ESCAP).

The RMC has reiterated its earlier forecast of heavy rainfall for south Tamil Nadu and the delta districts on Thursday, followed by a sharp increase in rainfall across the State from Friday.

Delta and adjoining districts are likely to receive heavy to very heavy showers on Friday, while heavy rain is expected to spread into north Tamil Nadu districts on Saturday as the weather system moves up along the coast.

After days of relentless rain in the southern districts, rainfall activity eased significantly on Wednesday.

During the 24 hours ending 8.30 a.m. on Thursday, only isolated light showers were reported.

Thangachimadam in Ramanathapuram district logged the highest rainfall at 3 cm, while Oothu in Tirunelveli – which experienced widespread flooding earlier this week – recorded 1 cm. In view of the expected intensification, the RMC has advised hoisting of storm warning signals at key ports including Chennai, Cuddalore, Ennore, Thoothukudi, Nagapattinam and Karaikal.

Mariners have been cautioned against venturing into the southwest Bay of Bengal and adjoining areas until further updates.

The latest forecast indicates isolated light rainfall over Kanniyakumari, Thoothukudi and Tirunelveli districts as the deep depression continues to organise over the ocean.

Meanwhile, Cyclone Senyar, presently centred over the coastal belt of northeast Indonesia and the adjoining Strait of Malacca, is expected to drift eastwards while maintaining its cyclonic storm intensity.

The RMC has clarified that Senyar poses no threat to Tamil Nadu and will not influence weather conditions over the State.

–IANS

aal/svn