IMD predicts cyclone genesis in Bay of Bengal, 20cm rain likely in Tamil Nadu, Odisha rains on Oct 19

By Sanjeev Kumar Patro

Bhubaneswar: Is any October peril brewing in the Bay of Bengal. Almost all the weather models have predicted formation of a low pressure area over the South Bay of Bengal today. This development will halt the withdrawal process of south west monsoon from Odisha and the central India.

As per the model forecasts, courtesy a trough line extending from central Arabian seas to south Bay of Bengal inducing vorticity over the south Bay of Bengal region between Sri Lanka and Andaman Islands, and the strong westerlies will be then seeding the formation of low Pressure Area by Oct 14/15.

MODEL DIVERGENCE

The IMD GFS model see it intensifying into a cyclonic storm within the next 48 hours, i.e by October 17, aided by higher sea surface temperature of over 29-32 deg C and higher Tropical Cyclone Heat Potential (TPCH) and low vertical wind shear.

However, NCMRWF’s NCUM, NCEP-GFS, ACCESS and ECMWF model show the system intensifying into a depression tracking west and as it nears Tamil Nadu.

Even as there is divergence among model over intensification, all agree on cyclone genesis. While IMD-GFS is seeing it a cyclonic storm coming, others rate the system intensifying into a depression.

As per IMD, NCMWRF, ACCESS and ECMWF model forecasts, the depression will cross over the Indian peninsula to emerge in the Arabian seas. The system will again intensify into a depression and track towards Oman. 

HEAVY RAINS, 50KMPH WIND LIKELY IN TAMIL NADU, KARNATAKA, KERALA

Under the influence of the brewing system, the State of Tamil Nadu will bear the brunt. Model forecasts predict over 20 cm rainfall over some coastal places in the State. The Chennai-Puduchhery-Nagpattanam region will receive heavy to very heavy rainfall.  

Karaikal in Puduchhery may record 23 cm rainfall on Oct 17. Almost all places in the State Capital Chennai may record over 10 cm rain on Oct 16/17. The whole of the peninsular region extending from Chennai to Mysore (Karnataka) and Kasargod (Kerala) will be recording heavy rainfall ranging to over 20 cm on Oct 17.    

The NCUM model predicts around 50kmph wind in the State of Tamil Nadu on Oct 16/17.

ODISHA RAINS

A look at the model forecasts shows when the system will emerge in Arabian Sea by around Oct 19, a trough line from the centre of the system will be extending up to Gangetic West Bengal, passing over Odisha.

Under its Influence, north Odisha districts, including places like State Capital Bhubaneswar, silver city Cuttack, will be recording rainfall in the range of 2cm. Some places in north Odisha may record rainfall to the tune of 4cm.