In a significant shift from the recent cold spell, Kolkata witnessed its minimum temperature crossing the 17°C mark for the first time in over seven weeks. On Friday, the mercury soared to a high of 17.9°C, which was 3.2 degrees above the normal seasonal average. This gradual surge in temperature hints at the arrival of warmer and more humid days ahead, but the Alipore Meteorological Office has indicated that relief might be on the horizon with a return of cooler conditions expected around the second week of February.
Western Disturbances Disrupting Wind Patterns
According to meteorological experts, the primary cause behind this temperature rise is a series of back-to-back western disturbances passing through northern India. These weather systems are disrupting the flow of the cold-bearing north-westerly winds, which typically keep temperatures in check during the winter months. HR Biswas, head of the Regional Meteorological Centre in Kolkata, explained, "At least three consecutive western disturbances are likely to affect northern regions until February 5. When these systems occur in succession, the north-westerly winds fail to reach our area, leading to a noticeable increase in temperature."
A Look Back at Kolkata's Winter Chill
The last time Kolkata recorded a minimum temperature in the 17°C range this winter was on December 5. Following that date, temperatures began to dip significantly, marking the onset of colder days. In fact, the very next day saw the mercury plunge to 14.5°C. Although temperatures occasionally rose above normal in December, they remained below average on most days, culminating in the chilliest New Year's Eve in eight years when the temperature dropped to 11°C on December 31.
The cold wave intensified in January, with the Met office recording 11.6°C on New Year's Day. The temperature hit a 13-year low for January on the sixth day of the month, plummeting to 10.2°C. So far this month, temperatures have stayed below normal on 20 days, with only 10 occasions showing a marginal rise above the average.
Short-Term and Long-Term Forecasts
The Met office anticipates that in the coming days, minimum temperatures will hover between 16°C and 17°C, while maximum temperatures are expected to range from 26°C to 28°C. Biswas added, "We can expect a slight dip in the minimum temperature by Saturday, but no significant changes are forecast for the next seven days. While extended forecasts may not be as precise as weekly predictions, our analysis suggests that temperatures are likely to decrease again by the second week of February."
Impact of Western Disturbances on Local Weather
Western disturbances typically bring winter rain to parts of northern India and snowfall at higher altitudes. However, their indirect effect on Kolkata's weather is more subtle. Met officials clarified that once a strong western disturbance passes, the city often experiences foggy skies and the resumption of north-westerly winds, which can make both daytime and nighttime conditions slightly colder. The Met office expects a break in these disturbances after January 5, which could pave the way for temperatures to fall once again in Kolkata.
This weather pattern underscores the dynamic nature of Kolkata's climate, where temporary warm spells are often followed by returns to cooler conditions, influenced by broader meteorological phenomena across the region.
