Delhi witnessed light rain in certain parts of Delhi-NCR and with cold winds the air quality deteriorated on Saturday as AQI registered 348 on the National Ambient Air Quality Index (NAAQI) and thus bringing the air quality under 'very poor category'.
According to Kuldeep Srivastava, Head of Indian Meteorological Department ( IMD ), Regional Weather Forecasting Centre, said that with a western disturbance impacting the entire region, pollution levels are not expected to worsen much over the weekend. Winds are likely to pick up during the day and settle the pollution levels, he said.
According to MeT, the wind speed reduced to 6kmph and the direction also changed from north-westerly to easterly on Friday.
While some areas in Haryana have received rainfall on Friday afternoon.
“The average wind speed in Delhi is likely to remain around 8-10kmph on Saturday and Sunday, which means that the air quality is likely to remain in the poor till Monday.”
“The western disturbance will pass on Saturday and the wind direction will change back to north-westerly,” Srivastava said.
According to System of Air Quality and Weather Forecasting And Research ( SAFAR ), the pollution monitoring agency, overall air quality has improved to Poor category from Very Poor.
Under the influence of fresh Western Disturbance (WD), isolated to scattered rainfall was seen.
“Surface-level winds are calm but picked up during the day. AQI improved during the day to the lower end of the Very Poor category in case of sufficient rain.” However, as an aftermath of WD, high moisture availability with higher air holding capacity, dense fog formation is expected (mainly during early morning hours). This triggered heterogeneous aqueous reactions to form secondary aerosols and lead to deterioration of AQI.”
“AQI is likely to deteriorate to the higher end of Very Poor by late December 13th,” it said in its short range weather forecast.
Meanwhile,the Central Pollution Control Board (CPCB) data shows that the overall AQI of Delhi was 295, in the poor category. The values of Suspended Particulate Matters ( SPMs ) PM 10 and 2.5 were 306 and 177 µgm-3.
On Thursday, the AQI settled at 284, also in the same category.