The India Meteorological Department (IMD) said on Thursday that the very severe cyclonic storm Biparjoy would intensify further and move towards north-northwestwards direction.
"VSCS BIPARJOY over eastcentral Arabian Sea, lay centered at 0530hrs IST of 08thJune, near lat 13.9N & long 66.0E, about 860km west-southwest of Goa, 910km southwest of Mumbai, would intensify further & move north-northwestwards.", IMD tweeted.
VSCS BIPARJOY over eastcentral Arabian Sea, lay centered at 0530hrs IST of 08thJune, near lat 13.9N & long 66.0E, about 860km west-southwest of Goa, 910km southwest of Mumbai, would intensify further & move north-northwestwards. pic.twitter.com/6HiSydw2qI— India Meteorological Department (@Indiametdept) June 8, 2023
Monsoon predictions for Kerala
Cyclone 'Biparjoy', the first storm brewing in the Arabian Sea this year, yesterday intensified into a very severe cyclonic storm with meteorologists predicting a "mild" monsoon onset over Kerala and "weak" progress beyond the southern peninsula under its influence.
The India Meteorological Department (IMD) on Wednesday morning said conditions are favourable for monsoon onset over Kerala within two days.
Meteorologists, however, said the cyclone has been impacting the intensity of the monsoon and the onset over Kerala would be "mild".
The MeT office said the very severe cyclonic storm would intensify further and move northwards during the next three days.
However, the IMD has not yet predicted any major impact on countries adjoining the Arabian Sea, including India, Oman, Iran and Pakistan.
Meteorologists say the tentative track of the system will be in the northward direction but storms at times defy the predicted track and the intensity.
Forecasting agencies said the storm has been undergoing "rapid intensification", escalating from just a cyclonic circulation to a very severe cyclonic storm in just 48 hours, defying earlier predictions.
Atmospheric conditions and cloud mass indicate that the system is likely to sustain the strength of a very severe cyclone till June 12.
What do the scientists say?
Scientists say cyclonic storms in the Bay of Bengal and the Arabian Sea have been intensifying rapidly and retaining their intensity for a longer duration due to climate change.
According to a study 'Changing status of tropical cyclones over the north Indian Ocean', the frequency, duration, and intensity of cyclones in the Arabian Sea have increased by about 20 per cent in the post-monsoon period and 40 per cent in the pre-monsoon period.
There has been a 52 per cent increase in the number of cyclones in the Arabian Sea, while very severe cyclones have increased by 150 per cent.
"The increase in cyclone activity in the Arabian Sea is tightly linked to the rising ocean temperatures and increased availability of moisture under global warming. The Arabian Sea used to be cool, but now it is a warm pool," Roxy Mathew Koll, climate scientist at the Indian Institute of Tropical Meteorology, said.
"The oceans have become warmer already on account of climate change. In fact, a recent study shows that the Arabian Sea has warmed up by almost 1.2 degrees Celsius since March, thus conditions are very much favourable for the rapid intensification of the system (Cyclone Bipajoy) so it has potential to sustain the strength for a longer period," Raghu Murtugudde, Professor, Department of Atmospheric and Oceanic Science, University of Maryland and IIT Bombay, said.
Mahesh Palawat, vice president (climate and meteorology) Skymet Weather, said the cloud mass is concentrated around this system and enough moisture is not reaching the Kerala coast. Though the criteria for monsoon onset can be met in the next two days, it will not be a thumping start.
After the onset over Kerala, the monsoon will remain "weak" until the storm degenerates around June 12, he said.
"The powerful weather system in the Arabian Sea may spoil the advancement of the monsoon deep inland. Under their influence, the monsoon stream may reach coastal parts, but will struggle to penetrate beyond the Western Ghats," Skymet Weather had said on Tuesday.
A senior IMD scientist said the southern peninsula will get rain under the influence of the cyclonic storm and a low-pressure system developing in the Bay of Bengal.
However, further progress of the monsoon beyond the southern peninsula will happen after the cyclone degenerates.
"It would not be the case of classic monsoon onset, satisfying all the given criteria. We would have scattered rains along the West Coast strip, but no inland penetration and widespread rains," Koll said.
The southwest monsoon normally sets in over Kerala on June 1 with a standard deviation of about seven days. In mid-May, the IMD said monsoon might arrive in Kerala by June 4.
Skymet had predicted the monsoon onset over Kerala on June 7 with an error margin of three days.
(With PTI Inputs)