Kolkata experienced a slight rise in temperatures on Sunday, but residents should not pack away their winter woollens just yet. The Regional Meteorological Centre (RMC) has forecast that the signature winter chill is set to make a strong comeback, with the mercury poised for a significant drop in the coming days.
Temperature Swing: A Brief Respite Before the Chill
On Sunday, the city saw a noticeable jump in both minimum and maximum temperatures. The minimum temperature climbed by 3.5 degrees Celsius to reach 15°C, while the maximum temperature increased by over a degree to settle at 23.9°C. Despite the rise, the maximum remained slightly below the normal seasonal average.
According to HR Biswas, deputy director-general of meteorology at the RMC, this temporary warming was caused by a low-pressure system off the southern coast. "Some clouds from the outer band of this system drifted into south Bengal, which briefly interrupted the flow of the northwesterly wind. This marginally pulled up the temperatures," Biswas explained. He added that although it was sunny for most of Sunday, a slight wind contributed to a persistent chilly feel.
Forecast: A Steady Drop in Mercury Ahead
The brief disruption is now over, and the northwesterly winds are regaining strength. This signals a return to colder conditions. The RMC bulletin indicates that the minimum temperature is expected to slide to 12°C-13°C on Monday.
A more pronounced drop is anticipated by Tuesday, with the minimum temperature likely to hit 12°C. The cold spell is expected to persist, with temperatures hovering around the 12°C mark potentially until next Sunday. The maximum temperature is also predicted to stay around 22°C during this period.
"There is no more system in the region that can block the wind. So, the chill will continue," stated Biswas, confirming the forecast of sustained cold weather.
Why This Winter Has Been Particularly Chilly
Kolkata has been experiencing a relatively severe winter season since mid-December, with temperatures consistently staying below normal. The city hit a season's low of 10.2°C on January 6, which was also the coldest night in Kolkata in 13 years.
Weather scientists attribute this prolonged chill to a significant lack of western disturbances (WDs). These extra-tropical storm systems, which originate in the Mediterranean region, typically interrupt the northwesterly winds during winter, leading to temporary temperature rises and sometimes unseasonal rain.
"There have been fewer systems that could have blocked the northwesterly. The chilly winds have been flowing in more steadily than previous years, keeping the mercury below the normal mark," a weather scientist explained. With clear skies expected to dominate, these winds will continue to transport cold air from the northwestern parts of the subcontinent, ensuring the chill persists across south Bengal for the upcoming week.
