Cyclone Phethai: North Indian Ocean source for major cyclones

Pattern of Phethai surprises researchers

The North Indian Ocean is the most potential source for formation depressions and cyclonic storms.

This year, it has already been the source for two cyclonic storms ‘Sagar’ (May 16 to 20, landfall in Yemen) and ‘Daye’ (September 19 to 22, landfall Odisha), one extremely severe cyclonic storm ‘Mekunu’ (May 21 to 27, landfall Yemen), two very severe cyclonic storm ‘Luban’ (October 6 to 15, landfall Yemen), and ‘Titli’ (October 8 to 12, landfall Odisha) and two severe cyclonic storms ‘Gaja (November 10 to 20, landfall Tamil Nadu) and the latest ‘Phethai’ (December 13 to 1-77, landfall Kakinada).

It has also been the source for development of about seven deep depression systems, this year.

According to S.S.V.S. Ramakrishna Rao of the Department of Meteorology, Andhra University, north Indian Ocean is a potential source of energy as it is a land-locked ocean.

This year, the north coastal region of Andhra Pradesh was directly affected by two severe cyclonic storms within a span of two months — Ttli and Phethai. "Daye had partially impacted the State," he said.

According to the professor, North Indian Ocean is the first amongst the oceans to experience the factor global warming, which includes warming of the oceans. "It is from 1999 that we are experiencing the rapid frequency of category cyclones, and all are brewing over this ocean. In 1999, we experienced the Odisha Super Cyclone, a category five cyclone, and since then we have witnessed at least 12 category 1 to 4 cyclones hitting the Indian Peninsula," he said.

Phethai

Though the weathermen say that October to December is the season for cyclones, as this is the period when the south-west monsoon ends and the north-east monsoon begins, researchers are a bit surprised with the pattern and movement of Phethai.

"It is the transition period and the possibilities of formation of a depression over the bay are high. But Phethai has surprised us all," said Prof. Ramakrishna. Rather than taking a curve and moving in the east north-west direction, it has moved straight in the northern direction, he said.

This phenomenon is new, as the cyclone system should have moved more towards Chennai, but it moved towards Kakinada and Visakhapatnam and it indicates two things: the weakening of north-east monsoon or the presence of steering ocean current due to cooler water temperature, said Prof. Ramakrishna.

The cloud cover is also thick, as the system sucked all the cloud formation from north-east, which is an indication of weaker north-east monsoon, he added.