A spell of thunderstorm on Thursday evening brought relief from heat and humidity.
The squall was followed by a sharp spell of rain. The two previous storms in Kolkata were marked by strong gusts of wind but the rain that followed was negligible.
On Thursday, the showers were more widespread than they were on the two previous occasions. The Met office recorded a wind speed of 63kmph in Alipore.
The squall lasted three minutes. At least one tree fell in Kolkata till 9pm. The tree fell under the AJC Bose Road flyover, opposite Calcutta Club. Traffic was disrupted for a while, a police officer said.
A trough of low pressure over northwest Uttar Pradesh to south Bangladesh via Gangetic Bengal triggered the storm, said a Met official.
“The trough drew moisture from the Bay of Bengal and led to the formation of thunderclouds," the official said.
The Met office had predicted “enhanced thunderstorm activities” in Bengal from May 23 to 27. “There is a possibility of thunderstorm activity on Friday. But the chances are low,” said Sanjib Bandyopadhyay, deputy director-general, IMD, Kolkata.