A cyclonic circulation moved into south Bengal from the Bay of Bengal on Thursday, triggering multiple spells of rain in Kolkata.
The system was over Gangetic Bengal and adjoining north Odisha on Thursday afternoon, said Met officials. It is expected to move further inland, towards Chhattisgarh, they added.
As the system moves away, the spread and volume of rainfall in Kolkata are likely to dip from Saturday, according to the forecast.
“The system was leading to the convergence of clouds. As the system moves further inland, the spread and intensity of the showers in Kolkata are likely to dip. Since the monsoon is here, the atmosphere has a significant amount of moisture. So, some rain is likely in Kolkata on Friday as well. But unlike Wednesday and Thursday, multiple spells are unlikely,” said G.K. Das, director, IMD Kolkata.
The Met office recorded around 12mm of rain in Alipore till 8.30pm on Thursday. The showers dragged the mercury down. The maximum temperature was 30.8 degrees, two notches below normal.
The Met office had on Wednesday said the conditions would be hot and humid when it did not rain.
“The circulation was right over Gangetic Bengal. So, a consistent cloud cover remained and the temperature was below normal. In the coming days, the Celsius is likely to go up gradually,” said a Met official.
According to figures collected from the pumping stations of the Kolkata Municipal Corporation, Maniktala, Ballygunge and Behala received around 15mm of rain on Thursday.
“The volume of rain in north Bengal might go up over the weekend,” said a Met official.