Celsius rises but cold run to continue - Walk the talk

Morning walkers on the Maidan on Friday. Picture by Sanjoy Chattopadhyaya

TT, Alipore: A cyclonic storm that had been biding time as a low-pressure area on the Bay of the Bengal for seven days moved into the Arabian Sea on Friday, instantly triggering a one-degree rise in the minimum temperature in Calcutta.

The official weather station in Alipore recorded a minimum temperature of 15.6 degrees Celsius at 5.30am. The previous morning had been the coldest of the season at 14.6 degrees.

Meteorologists foresee no further surge in the minimum temperature in the next three days. "The minimum temperature should stay in the range of 15 to 16 degrees Celsius for the next three days because of the continuous flow of cold winds from the north," said Sanjib Bandyopadhyay, deputy director general of the India Meteorological Department, Calcutta.

The city had been enjoying cool mornings and nights since November 22, when the minimum temperature fell five degrees to 16.6.

A weather system originating in the Gulf of Siam had been the catalyst in this pre-winter cold spell. The system moved into the Bay of Bengal last week, where it intensified into a cyclonic storm and moved into the Arabian Sea.

"When the cyclone moved west, the entire network of winds around the Indian landmass shifted in the same direction. The consequent decrease in the volume of cold winds entering Calcutta made the minimum temperature go up a notch on Friday," Bandyopadhyay said.

Since the general direction of the wind flow at this time of the year is northwest, the minimum temperature won't rise abruptly at least till the weekend.

To get an idea of what will happen after that, Met officials have been tracking another well-marked or intense low-pressure area that has formed on the south Bay of Bengal. The system is expected to intensify into a depression by Saturday and move west towards the eastern coastline.

"This system is tipped to inch towards the Tamil Nadu-Andhra Pradesh coast. If it ends up closer to Andhra Pradesh, there would be moisture incursion into Calcutta and some resistance to the flow of cold winds from the north. But we don't see the minimum temperature rising before three to four days," a weather scientist said.