Most towns and cities in northwest India recorded poor and very poor category air on Saturday. While Delhi has an air quality index (AQI) of 324 in the very poor category, NCR cities of Faridabad, Gurugram and Noida recorded poor air quality. The air quality is likely to deteriorate further from December 27 due to a change in wind speed, associated with an approaching western disturbance.
“The wind speed increased to 10 to 15 kmph on Friday which helped improve the air quality but we are expecting AQI to deteriorate again on December 27 and 28 to the lower end of the very poor or severe category. When a western disturbance approaches, winds slow down, resulting in an accumulation of pollutants,” said VK Soni, scientist at IMD’s air quality management division.
A moderate intensity western disturbance is likely to lead to a substantial fall in minimum temperatures once again at the end of the year. It will be preceded by a gradual rise in minimum temperatures by 2 to 3 degree C in the next three days, from December 25 to 27, followed by the 3 to 5 degree C drop over northwest India between December 28 and 30.
“Minimum temperatures are likely to drop by around 3 to 5 degree C after December 28. Winter is at its peak during December end and January beginning. But because of the influence of a western disturbance, it can be harsher. Both October and November have been colder than usual this year, but December has been mild so far,” said RK Jenamani, senior scientist, national weather forecasting centre.
The western disturbance is likely to affect Western Himalayan region and cause widespread snowfall over Jammu and Kashmir, Ladakh, Gilgit, Baltistan, Muzaffarabad; scattered snowfall over Himachal Pradesh, Uttarakhand and isolated rain or thundershowers over adjoining plains of northwest India during December 27 and 28.
“After the passage of the system and under the influence of the consequent strengthening of cold and dry north-westerly or northerly lower-level winds, cold wave conditions will set in again,” IMD said in its Friday bulletin.
Cold wave to severe cold wave conditions are likely in isolated pockets over Punjab and Haryana, Chandigarh and Delhi and ‘cold wave’ conditions are likely in isolated pockets over Uttar Pradesh, north Rajasthan and north Madhya Pradesh during December 28 and 29.
Ground frost conditions are likely over parts of Punjab, Haryana, Chandigarh, Delhi, Uttarakhand, Himachal Pradesh and north Rajasthan, during December 28 and 29.
