Calcutta experienced a hot and dry morning on Wednesday but a trough of low pressure pushed up moisture content in the air later in the day, brightening chances of light showers in the next two days.
However, similar weather systems deceived the city recently, losing intensity unexpectedly or bringing rainfall only to the western districts like Bankura, Burdwan and West Midnapore.
On Wednesday, the city’s maximum temperature was 37.1 degrees Celsius, a notch above normal and same as the maximum on Monday and Tuesday.
But the minimum relative humidity fell overnight from 30 to 25 per cent, resulting in the dry heat from morning till noon.
As the day wore on, moisture incursion started because of the low-pressure trough.
“The wind was so dry that I was forced to cover my face with dupatta while travelling down the Bypass in a taxi around 11am. But I was sweating profusely on my way back around 3pm,” said Rupsa Mitra, 29, an employee of a private firm.
At 2.30pm, the temperature was 36.8 degrees Celsius and the relative humidity 34 per cent. The discomfort index, the effect of heat and humidity on the human body, was 61.4 degrees, more than six degrees above the comfort level.
The discomfort levels are likely to go up in the city on Thursday because of unabated flow of moisture from the Bay to the city.
“A trough of low pressure extending from north Bengal to Odisha is drawing moisture inland. The trough is likely to stay active for the next 48 hours,” said Gokul Chandra Debnath, director, India Meteorological Department, Calcutta.
“We expect partly cloudy skies because of the the moisture flow and heat. Thunderstorms are likely in the western districts. Even if they hit the city, they are unlikely to be strong.”
The western districts experienced thundershowers on Wednesday evening, too, but the clouds did not reach Calcutta.
According to Met records, Calcutta usually receives two squalls in March and three in April on an average.
But this year till the middle of April there was only one tempest — on March 25. The storm blew at 58kmph, tearing down billboards and felling trees as the city was lashed by a steady shower for 30 minutes.
As things stand, Calcutta is unlikely to get another such shower in at least the next couple of days.