In a sign of rising sea surface temperature, the Arabian Sea this year has seen the highest-ever cyclonic disturbances (CDs) — four cyclonic storms and three depressions or deep depressions.
The Arabian Sea is likely to witness two more simultaneous cyclonic storms, Pawan and Amphan, in the next 24 hours, officials said.
According to India Meteorological Department (IMD), sea surface temperatures (SST), or simply, the temperature of seawater recorded at the surface, was higher than normal over the Arabian Sea since October, towards the culmination of the southwest monsoon season.
While the IMD pegs normal CDs over Arabian Sea at 1.7 per year, six cyclonic disturbances were witnessed over Arabian Sea in 1998. In October, for the first time since 1965, two cyclonic storms, Kyarr and Maha, had prevailed simultaneously over the Arabian Sea.
Out of the four cyclones over the Arabian Sea this year, ‘Vayu’ and ‘Hikka’ were ‘very severe cyclonic storms’, while ‘Maha’ in October was an ‘extremely severe cyclonic storm’ and ‘Kyarr’ that brought unseasonal rainfall to Karnataka, Maharashtra and Gujarat was a ‘super cyclonic storm’.
While cyclonic formation over Arabian Sea in October-November is rare, it is more frequent and common over the Bay of Bengal.
Last month, M Rajeevan, secretary of the ministry of earth science, had said that more frequent cyclones were likely in the coming years. In 2019, 11 cyclonic disturbances developed over the north Indian Ocean, including four over Bay of Bengal and seven in Arabian Sea. A total of seven cyclones — Pabuk, Vayu, Fani, Hikka, Kyarr, Maha and Bulbul — were recorded in the Arabian Sea and Bay of Bengal in 2019 alone.
Meanwhile, following a number of active weather systems in the Arabian Sea, wind and overall weather systems along the west coast has lead to cloudy weather and a delay in the winter season. IMD’s Santacruz observatory on Wednesday recorded a maximum temperature of 34.7 degrees Celsius, at least one degree above normal. A minimum temperature of 23.4 degrees Celsius, four degrees above normal, was also recorded. IMD has forecast cloudy weather for the next 48 hours in Mumbai.