The city and most parts of south Bengal were pounded by heavy rainfall and strong gusts of wind since Friday evening as a depression over the Bay of Bengal kept getting stronger as it moved through south Bengal.
The Met office has issued a heavy rain alert for Bankura, West Midnapore, Jhargram, Purulia, West Burdwan and Birbhum on Sunday as the system moves westwards. In Calcutta, the conditions are likely to remain cloudy and more than one spell of rain is expected on Sunday.
The depression was over northeast Bay on Friday night. It crossed the Bangladesh coast around 10.30pm on Friday and had intensified into a deep depression by the early hours of Saturday. It remained so till late Saturday evening.
Met officials had expected the system to lose steam after turning into a depression. “But it was feeding on moisture from the Bay continuously,” said H.R. Biswas, head of the weather section at the Regional Meteorological Centre, Calcutta.
The system entered Bengal through North 24-Parganas and was around 20km from Calcutta on Saturday afternoon.
Calcutta hardly got sunlight on Saturday. Cars on city roads in the afternoon had their headlights switched on. The shopping hubs and malls, already witnessing a slump because of the ongoing protests, suffered the additional brunt of the elements.
Salt Lake, where the junior doctors have been on protest demanding justice for the postgraduate trainee found raped and murdered at RG Kar, got around 70mm of rain between Friday afternoon and Saturday afternoon. The sky kept pouring even after that.
Overhead tarpaulin sheets strung up on bamboo poles served as roofs but water trickled down their ends. However, the weather seemed to have little effect on the protesters as they kept singing slogans and songs, even as chief minister Mamata Banerjee visited them.
Between 11.30am on Friday and 11.30am on Friday, the Met office recorded 80mm of rain in Alipore, the official record keeper for Calcutta. Most of the rain happened after Friday evening. It rained almost incessantly through the night. The showers came accompanied by howling winds now and then.
In Met parlance, more than 60mm of rain in 24 hours is considered heavy.
The rain continued throughout Sunday, picking up steam around 6.30pm.
Swathes of south Bengal have been battered by heavy rain and winds since Friday evening. Several houses were damaged in Namkhana, Patharpratima and neighbouring areas in South 24-Parganas. Low-lying areas in the coastal belts were flooded.
Between Friday morning and Saturday morning, Contai in East Midnapore received 180mm of rain.
Digha, in the same district, got 120mm. Sagar Island and Diamond Harbour, both in South 24-Parganas, got 110mm and 90mm, respectively. Durgapur and Panagarh in West Burdwan got 100mm and 90mm, respectively.
Several other places in Birbhum and Murshidabad also got over 70mm of rain.
A Met bulletin issued on Saturday afternoon said: “The deep depression over Gangetic West Bengal and adjoining Bangladesh moved west-southwestwards with a speed of 18kmph during past six hours and lay centered at 11.30am on Saturday over Gangetic West Bengal, 20km south-southwest of Kolkata, 170km southeast of Bankura, 220km east-southeast of Jamshedpur (Jharkhand) and 320 km east-southeast of Ranchi (Jharkhand).
“It is likely to move nearly westwards across Gangetic West Bengal and maintain its intensity of deep depression today. Thereafter, it will continue to move nearly westwards across Jharkhand and north Chhattisgarh as a depression during subsequent 48 hours,” the bulletin said.