Sharp spells of rain lashed the city through Friday night and into the early hours of Saturday, long after a deep depression had entered land near Digha.
The tail of the system and the clouds in the outer band triggered the rain, said a Met official.
“The system started making landfall before 7pm on Friday. The centre of the system completed landfall between 7pm and 8pm. But the tail and the clouds in the outer band took more time to enter land,” said G.K. Das, director of India Meteorological Department, Kolkata.
Around Friday midnight, the city was lashed by a strong spell of showers, accompanied by gusts of wind.
Arka Sarkar, a Tollygunge resident, was driving back home from Sector V late at night.
“The showers had reduced visibility and it was scary,” he said. Between 8.30 am on Friday and 8.30 am on Saturday, the Met office recorded around 45mm of rain in Alipore.
Between 8.30 am and 8.30 pm on Friday, the volume was around 22mm. Digha received close to 200mm of rain in the same time. In Met parlance, 60mm of rain in 24 hours qualifies as heavy.
Before Friday and Saturday, the most rain that Kolkata received this month was on August 2, when parts of the city and its northern suburbs received heavy rain. But the distribution was skewed and many other pockets were dry.
But the last rain was uniform and widespread.
The latest system, the strongest on the bay of Bengal so far this monsoon and the closest to Kolkata, has provided momentum to the monsoon currents, said Met officials.
The monsoon trough is passing over Digha now. The forecast for the coming days is that of typical monsoon weather.
“The sky will remain partially cloudy. Expect some rain but when it does not, the weather will be sweaty and sultry,” said a Met official.