Cold wave likely to make a return to the city, says MeT dept

The city woke up to a relatively warmer morning on Friday, when the minimum temperature was recorded at 7.7 degrees Celsius — up from 7.2 degrees Celsius a day before. However, isolated cold pockets were observed across the National Capital Region(NCR), including in Delhi, where the Safdarjung observatory recorded a minimum temperature of 4.2 degrees Celsius, indicating a ‘cold day’.

Officials in the India Meteorological Department (IMD) said that cold day conditions occur either when the maximum temperature remains under 10 degrees or the minimum temperature remains less than 4.5 degrees Celsius or 6.4 degrees Celsius below normal. Such cold day conditions are likely to spread to other parts of Delhi-NCR, including Gurugram, over the next two days. This dip, they said, is due to a fresh western disturbance currently affecting Himalayan regions in the north, causing heavy snowfall in parts of Jammu and Kashmir.

Kuldeep Srivastava, head of the regional forecasting centre at the IMD, said, “We had originally predicted that cold drafts would start blowing over north India around January 25, but some parts have already begun to feel the influence of the weather system. Gurugram will also experience a dip in the minimum temperature over the weekend.”

Cooler conditions were more prominent during the day on Friday, when the maximum temperature dipped to 17.1 degrees Celsius — down from 20.2 degrees Celsius on the previous day. As per the IMD’s seven-day forecast for Gurugram, the minimum temperature is likely to dip to as little as four degrees Celsius by Monday, while the maximum temperature may dip to 16 degrees Celsius.

Srivastava added that the IMD has sounded a cold wave alert for north India for the next few days. Unlike a cold day, a cold wave is characterised by a simultaneous dip in both minimum and maximum temperature readings. “After the weather system passes, there will be a lot of residual moisture in the atmosphere and this will bring down the daytime temperature as well. In the mornings, there will be dense fog,” Srivastava said.

The dip in daytime temperature on Friday was accompanied by calmer winds, which, in turn, led to a significant deterioration in Gurugram’s air quality. The city recorded an AQI of 315 (very poor) on the CPCB’s daily air quality index bulletin (up from 234 the previous day, indicating poor air). As per the early air quality warning system for Delhi-NCR, “Air quality is likely to... remain in very Poor category on 23.01.2021 and lower end of very Poor to Poor category on 24.01.2021.”