At 20.7°C and 7° above normal, Kolkata has its warmest late-December night in 50 years – Times of India

KOLKATA: Tuesday’s minimum temperature hit 20.7°C in the city, making it Kolkata’s warmest second-half-of-December night in the last 50 years, with the mercury shooting seven degrees above the normal. And even though the Met office expects a temperature drop from Wednesday onwards, the minimum would likely continue to remain above normal.
The chill is missing because of a strong high-pressure zone over the Bay of Bengal, said weather experts. This has been blocking the cold winds while facilitating the incursion of warm and humid south-westerly winds, pushing up the temperature.
In fact, Tuesday’s maximum temperature – 27.9°C – was also the highest for December 27 in the past few years, according to the Met office.
“It is not unusual for the minimum temperature to stay above 20°C at the beginning of December,” said G K Das, director (weather), Regional Meteorological Centre, Kolkata. “But, in the period after December 15, we expect it to dive to around the normal mark (13°C) and below. We have not come across such a high minimum temperature in the last half of December in the last 50 years,” he added.
The Met office blames a dynamic high-pressure zone over the Bay of Bengal for keeping the chill at bay. Because of this system, the city is currently getting warm and humid south-westerly winds, pushing up the mercury. This wind system is predominant in the neighbouring states of Jharkhand, Bihar and Odisha as well.
“We are expecting cool and dry north-westerly winds from central India to start reaching the city by Wednesday, pushing the minimum temperature to around 18°C, and a further dip of another three to four degrees by Thursday,” Das added.
The north-westerly wind is expected to lose intensity by Friday, causing the mercury to rise again by one or two degrees above the normal. The Met office expects the minimum temperature to hover around 17 °C on New Year’s Eve. December 17 was the coldest in Kolkata this year, when the minimum temperature had nosedived to 13.2 °C, two degrees below the normal.
From there, the mercury started to rise gradually, remaining above 20 degrees in the past two days. Das said global warming was one of the factors influencing the overall temperature rise. But he also said “synoptic” (localised weather systems) features also had a bearing on how the mercury behaved.