A spell of bright sunlight lifted the mood of Kolkatans on Thursday morning after days of gloomy weather but that was short-lived.
By afternoon, ominous dark clouds had taken over the sky once again. Eventually, many areas in Kolkata and adjoining areas received a spell of thunderstorm on Thursday but the volume of rain was not much.
The clouds were from the Bay of Bengal and on their way to central India, where a cyclonic circulation was positioned on Thursday. The system is a weaker version of the low-pressure belt that was over Kolkata a couple of days ago, triggering torrential rain that the city had not seen in close to 15 years.
“The cyclonic circulation is over Madhya Pradesh. It is being fed moisture by both the Bay of Bengal and Arabian Sea. The clouds over Kolkata were from that moisture,” said a Met official.
A system over eastern India is fed by the Bay. A system in central India is fed by both the Bay and the Arabian Sea. A system on the western coast is fed by the Arabian Sea.
“As the present cyclonic circulation veers further west, it will be fed mainly by the Arabian Sea, which means lesser clouds from the Bay on Friday. The sky in Kolkata will be brighter for longer phases from Friday,” he added.
The monsoon trough is active but passes over Odisha into the Bay of Bengal, reasonably south of Kolkata to have any formidable impact on the city, he said.
The city may receive occasional rain but the weather is likely to keep improving till Sunday, according to the Met forecast.
Another low-pressure area, likely to form over the northeast and adjoining east-central Bay of Bengal by Friday, is due to move towards the Odisha coast and hit land by Sunday.
“East Midnapore is likely to get heavy rain on Sunday. The other areas of coastal Bengal, including Kolkata, are likely to see an increase in rainfall activity on Sunday and Monday,” a Met alert said.
“It is still too early to forecast the volume of rain in Kolkata because of the system. It depends on the route it takes and the area of landfall,” said the Met official.