A cyclonic circulation that formed over the South Andaman Sea on Wednesday is set to transform into a depression by this weekend.
It is still too early to predict if the system will intensify into a cyclone, said Met officials.
But May is a ripe time for tropical cyclones and the possibility is not ruled out. If the system intensifies into a cyclone, it will be the third in May in three consecutive years after Amphan in 2020 and Yaas in 2021.
“The cyclonic circulation is likely to become a low-pressure area on Wednesday. Over the subsequent 48 hours, it is likely to further intensify into a depression,” said Ganesh Kumar Das, director, India Meteorological Department, Kolkata.
“What happens beyond that remains to be seen. It is still too early to predict if the system will turn into a cyclone or say which coast it will head to,” said Das.
The system will be moving in a north-northwestward direction towards the Bay of Bengal, he said.
Andhra Pradesh, Odisha and Bengal are all possible destinations, as are Bangladesh and Myanmar.
May is a fertile time for cyclones on the Bay because of higher sea surface temperature, a key requirement for the formation of cyclones.
But there are other factors that can make or break a cyclone, said Das.
“A strong vertical wind shear, which removes heat and moisture from the core, can be fatal for a cyclone. As the system nears land, dry westerly winds in the upper reaches of the atmosphere can also be damaging,” he said.
In December, Cyclone Jawad lost steam as it neared land because of multiple factors. One of them was the difference in sea surface temperatures.
The sea surface temperature was higher on the southeast and west-central Bay of Bengal. As the system moved closer to the coast, the sea surface temperature became colder.
But that was in winter. In May, the sea surface temperature is likely to remain favourable for the new system, said weather scientists.
Met officials are hoping for a clearer understanding of the system over the next couple of days.
“The long journey spanning thousands of kilometres over the sea is full of uncertainties. Once the system turns into a depression, we will have a much better understanding,” said Das.
For now, the Met office has only issued an “enhanced rainfall warning” for Andaman and Nicobar islands from May 4 to 8.
In Kolkata, thunderstorm activities are likely to subside after another squall, said a Met official.
“Wednesday saw the formation of new thunderclouds over Jharkhand. The clouds were over Ranchi in the afternoon. They are moving towards Kolkata and are expected to trigger another round of thundershowers,” the official said on Wednesday evening.
After the thunderstorms abate, the temperature will go up again, he said.
“By this weekend, the maximum temperature is likely to be around 36 degrees,” the official said.