A cyclone brewing on the Bay of Bengal and making its way towards the Odisha-Andhra Pradesh coast could bring intermittently intense rainfall over three days leading to Durga Puja before the skies clear for the festival spirit to shine through.
Satellite images on Monday showed a high possibility of rain in Calcutta and the surrounding districts between Wednesday and Friday, according to weather scientists. Whether these projections will play out depends on the trajectory that the cyclonic storm takes.
The Met office hopes to have a clearer picture of the system’s progression by Tuesday.
“There can be a spell of heavy rain in Calcutta on Thursday, although it is unlikely to rain throughout the day. If that spell does happen, 60mm or more rain can potentially come down,” said Sanjib Bandyopadhyay, the deputy director general of the India Meteorological Department (IMD), Calcutta.
Heavy rain in meteorological parlance is any volume between 60mm and 120mm of rain in 24 hours. On Wednesday, light to moderate rain is expected, which translates into a count of 59mm in 24 hours.
The gloominess, if it does happen, will hopefully be dispelled by Saturday. The effect of the cyclone is tipped to wane by then, leaving “stray localised showers” as the only threat to the festivities.
For Calcutta, rain has been the real Mahishasura every Durga Puja in recent years except 2015, which did not bring a drop of rain during the festival.
Two years before that, Cyclone Phailin (pronounced Pilin) had crashed into Odisha on Ashtami, triggering a downpour Navami onwards. The rainfall got more intense on Dashami and Ekadashi.
In the past two years, there was some amount of rain almost every day during Durga Puja. In 2016, 38.7mm of rain was recorded on Ashtami. The combined volume between Sashthi and Ekadashi was 82.7mm (see chart).
On Monday, the weather system looming over this festive period was a depression on the east-central Bay of Bengal, around 950km south of Calcutta. The weather office expects the system to intensify into a deep depression the next day and a cyclonic storm on Thursday.
The cyclonic storm will be called Titli, a name given by Pakistan.
“We expect clouding in Calcutta to start from Tuesday afternoon and rainfall to start on Wednesday. The intensity of rainfall could increase on Thursday, when the cyclone is likely to take shape. Rain will continue on Friday. From Saturday onwards, we expect the skies to clear,” said Bandyopadhyay said.
An IMD statement in the evening said the depression was travelling in the north-westerly direction towards the Odisha-Andhra coast, but did not mention if the system would make landfall there, if at all.
A weather scientist said that if Calcutta and its surroundings received intense rainfall this week, the residual moisture would remain a factor. “What it means is that even if the sun is back, thunderclouds can form and trigger localised showers.”
The Telegraph