BROLLY BRIGADE: Commuters caught in Friday’s shower. Picture by Pabitra Das

The weatherman has warned of heavy rain in the city on Saturday.

The monsoon is “very active” over Gangetic Bengal, said G.C. Debnath, director of the weather section at the Regional Meteorological Centre in Alipore. “The intensity of the monsoon current has increased over the past 24 hours. We expect heavy showers in Calcutta and south Bengal over the next 24 hours.”

There are other factors behind the development of thunderclouds over Calcutta. “A trough of low pressure over the city is sucking in moisture from the Bay of Bengal,” explained a Met official.

The clouds caused a shower on Friday afternoon. “On Saturday, a downpour is expected. Fishermen in the coastal districts have been asked not to venture out to the sea,” added the official.