Low-pressure area likely to form over Bay of Bengal, ease rain deficit in State

The season’s next low-pressure area is likely to form over the southeast Bay of Bengal around Friday and intensify into a depression by November 15, raising expectations of widespread rainfall to overcome shortfall in various districts and boost water sources.

The Regional Meteorological Centre has so far forecast moderate rainfall over southern districts till November 15, with rainfall likely to shift to north Tamil Nadu next week. November is the wettest month of the year for many districts, including Chennai, Nagapattinam, Cuddalore and Tiruchi, which receive their maximum share of annual rainfall during this time.

This Northeast monsoon, districts like Cuddalore, Mayiladuthurai, Thanjavur, Chengalpattu and Tiruvarur, are among the districts that continue to record a rainfall deficit. The weather agency has said an upper air cyclonic circulation over south Andaman Sea and neighbourhood is expected to trigger the formation of a low pressure area over southeast Bay of Bengal on Friday.

It is further likely to gather strength as depression by November 15. Officials of the RMC, however, noted that the rainfall impact zone could be identified only after the system gains strength and its direction becomes clearer.

V.R.Durai, Head, Regional Weather Forecasting Centre, RMC, said the weather agency is monitoring for chances of the system becoming a cyclone and the prospects of rainfall over TN. “Normally, the weather systems that form over southwest Bay of Bengal have a tendency to move towards Tamil Nadu.

Cyclone Murasu also had its genesis in the same region as the upcoming system. The initial circulation that influenced Cyclone Murasu was over south Andaman sea. We will get more clarity on its movement in one or two days,” he said.

The current weather pattern in parts of the State is being influenced by an upper air cyclonic circulation over Gulf of Mannar and neighbourhood. The RMC has retained its forecast of moderate rainfall over south and delta districts till Sunday.

Those in north coastal belt may receive light rainfall till Sunday and witness an increase in rainfall intensity from November 16. However, prospects of widespread and heavy rainfall would depend on the track and intensity of the fresh weather system, officials added.