Parts of northwestern India records cold wave, very poor air

New Delhi, Dec 25: Several states in north-western India, including Delhi, Noida and Ghaziabad, recorded "very poor" to "severe" air quality on Friday amid a drop in wind speed that has slowed down the dispersal of pollutants. In the national capital, the air quality was likely to remain in the "very poor" or "severe" category.

The ventilation index, which defines the ability of the atmosphere to disperse contaminants, over Delhi was expected to be 5,000 m2/s. A ventilation index below 2,350 is considered poor.

According to the India Meteorological Department (IMD), a cold wave persisted over several parts of India including Jammu and Kashmir, Punjab and Haryana. No significant change in minimum and maximum temperatures was likely during the next two days.

Cold wave conditions are likely in isolated pockets in Punjab, Haryana, Chandigarh, and Himachal Pradesh on Friday.

A cold wave occurs in plains when the minimum temperature is 10 degrees Celsius or below and 4.5 notches lesser than the season's normal for two days. It is also declared when the minimum temperature is less than 4 degree Celsius in the plains.

Dense to very dense fog was also likely over Punjab, northern Uttar Pradesh and Haryana on Friday and Saturday.

"An active Western Disturbance is likely to affect Western Himalayan Region from tomorrow [Saturday] which is likely to cause scattered to fairly widespread rainfall/snowfall over Jammu, Kashmir, Ladakh, Gilgit, Baltistan & Muzaffarabad; isolated to scattered rainfall/snowfall over Himachal Pradesh, Uttarakhand and light rain/thundershowers over adjoining plains of northwest India on December 27 and 28," an IMD bulletin said.

Kuldeep Shrivastava, who heads the Regional Weather Forecasting Centre, said the approaching Western Disturbance may cause light rain in Delhi on December 27 following which temperatures are likely to fall again.