Monsoon wet spell to pause over Tamil Nadu; rain likely to revive on November 1

Tamil Nadu is in for a brief hiatus from the monsoon wet spell, with rainfall likely to taper off over most parts of the State from Tuesday. Most parts of the State may begin to experience largely dry weather till November 1 except for isolated rainfall of moderate intensity over the southern and Western Ghats districts.

The Northeast monsoon, which was in its active phase, brought the much-needed rainfall over the State since its onset in mid-October. Tamil Nadu has recorded an overall rainfall of 21.5 cm, 58% above the monthly average. The State receives an average of 44 cm of rainfall during the entire season.

Officials of the RMC said the intensifying cyclonic storm Arnab is expected to draw moisture-laden winds towards it. It is likely to make landfall between Bapatla and Visakhapatnam, close to Yanam, as a very severe cyclonic storm by Wednesday.

As the cyclone moves away from the Tamil Nadu region, dry weather would return over the State, bringing only isolated rainfall over south and Western Ghats districts till the month-end. The monsoon is interspersed with dry spells, which may sometimes last longer, said V.R. Durai, head, Regional Weather Forecasting Centre, RMC.

With the moisture drawn away from the State, winds would shift from the seasonal northeasterly to dry, westerly or northwesterly winds. The prevailing low pressure area over Bay of Bengal and adjoining south coastal Tamil Nadu would also merge with the intense storm by Tuesday. However, cool winds from the Arabian sea would facilitate cloud cover and sustain rainfall over south Tamil Nadu this week, he said.

The absence of widespread cloud cover and rainfall could bring back warm weather over parts of North Tamil Nadu between October 28 and 30. The RMC has forecast a rise in temperatures by two to three degrees Celsius at a few places in the northern districts.

The weather agency expects a fresh cyclonic circulation to form over southwest Bay of Bengal and revive monsoon activity over the State, particularly north Tamil Nadu and Western Ghats districts, from November 1.

On the Chennai’s ageing S-band radar that is frequently under maintenance, officials said the radar on Rajaji Salai is being repaired.

Central Chennai Member of Parliament Dayanidhi Maran also raised concerns over the radar’s frequent downtime. In a social media post, he recalled letters written and questions raised on the issue in the past. Noting that it would put Chennai’s disaster preparedness at risk, Mr. Maran said a representation has been made to the Prime Minister once again for time-bound replacement and reliable backup coverage.

Officials, however, said alternative weather monitoring tools, including X band radar at NIOT Pallikaranai and Sriharikota, were available to monitor the weather. Satellite observations would also help track weather developments beyond 500 km at frequent intervals and the ongoing repair work would not affect weather predictions.

Orders have been placed to replace the old radar and the city would have a new radar next year, officials added.