Is Another Severe Cyclonic Storm Brewing Over Bay? Know What Weather Models Indicate

Bhubaneswar: Is another storm brewing over Bay of Bengal, two months after Cyclone Dana hit Odisha coast in early hours of October 25?

According to the India Meteorological Department (IMD), an upper air cyclonic circulation is likely to form over the South Andaman Sea and adjoining areas around November 21 and intensify into a low-pressure by November 23.

“After intensifying into a low-pressure, it is likely to continue moving west-northwestwards and intensify into a depression over the southwest Bay of Bengal during the subsequent two days. A continuous watch is being maintained for further intensification and movement of the system towards the Tamil Nadu-Sri Lanka coasts,” it said on Wednesday.

It added that Intense Observation Phase may be declared for Andaman Islands during November 20-23, East coast of Sri Lanka during November 24-25, Tamil Nadu & Andhra Pradesh coasts during November 24-27.

However, different weather models suggest further intensification of the system into a severe cyclonic storm.

IMD GFS is indicating cyclonic circulation over South Andaman Sea & adjoining Equatorial Indian Ocean around November 21, low-pressure area over southeast Bay of Bay around November 23 with nearly west-northwestwards movement and intensification into depression around November 24/1200 UTC (5.30 hours behind IST), severe cyclonic storm near South Sri Lanka on November 26. Thereafter, it is indicating the system to cross over southeast Sri Lanka and cross South Tamil Nadu near Tuticorin around November 26/0000 UTC.

NNCEP GFS is indicating cyclonic circulation over South Andaman Sea around November 20/1200 UTC, low-pressure area over southeast Bay of Bengal around November 23 with west-northwestwards movement and intensification into depression on November 24/ 0000 UTC. It is indicating west-northwestwards movement towards South Sri Lanka till November 26/0000 UTC with intensification into a severe cyclonic storm. Thereafter, the system is indicated to follow northwestwards path, weaken gradually and cross Andhra Pradesh-Tamil Nadu coasts between Nellore & Chennai around November 29/1200 UTC.

NCUM (R) is indicating strengthening of easterly waves till November 24, low-pressure area over southwest Bay of Bay close to Southeast Sri Lanka on November 25 with west-northwestwards movement across Sri Lanka and South Tamil Nadu during November 26-27.

ECMWF is indicating cyclonic circulation over South Andaman Sea and adjoining Equatorial Indian Ocean around November 21, low-pressure area over southwest Bay of Bay around November 23, nearly west-northwestwards movement & intensification into depression around November 25 and reach close to South Sri Lanka around November 25/1200 UTC as a depression/deep depression. Thereafter, it would follow north-northwestwards path and cross South Tamil Nadu near Thanjavur (North of Tuticorin) as a low pressure area around November 27/0600 UTC.

“Guidance from various models indicate formation of cyclonic circulation over South Andaman Sea around November 21, low-pressure area over southwest Bay of Bay around November 23, and depression over southwest Bay of Bengal around Novemeber 24. There is large divergence among various models on peak intensification of system. GFS group of models are indicating higher intensification, ECMWF up to depression/deep depression stage and NCUM up to low pressure area stage. However, there is good consensus among various models that the system would weaken before crossing coast Tamil Nadu coast. Most of the models are indicating west-northwestwards to northwestwards movement towards Sri Lanka-South Tamil Nadu coasts. Only NCEP GFS is indicating initial west-northwestwards movement followed by north-northwestwards movement and crossing over Andhra Pradesh coast,” the IMD said.

The weather agency has forecast isolated very heavy rainfall very likely in Tamil Nadu, Puducherry & Karaikal on November 20 and 26, coastal Andhra Pradesh, Yanam & Rayalaseema on November 26. Isolated heavy rainfall may also occur in Lakshadweep on November 20, Kerala & Mahe on November 20 & 26, Nicobar during November 22-24 and Tamil Nadu, Puducherry & Karaikal on November 25.

Bhubaneswar regional centre’s director, Manorama Mohanty, however, said it is too early to forecast its impact on Odisha.