Air Quality and Weather Bulletin for Delhi NCR (28.05.2020)

1. As per AQ-EWS models the air quality over Delhi NCR is likely to deteriorate marginally but reach in upper end of Moderate category 28.05.2020. The air quality is likely to deteriorate further owing to strong winds and duststorm and reach in upper end of Moderate to Poor category on 29.05.2020. The air quality is likely to improve marginally but remain in Moderate category on 30.05.2020. The predominant pollutant is PM10 due to higher dust load in atmosphere owing to strong winds, dust storms and transported dust.

 2. The predominant surface wind is likely to be coming from East direction of Delhi having wind speed upto 25 kmph with partly cloudy sky and possibility of very light rain/drizzle accompanied with gusty winds (speed 30-40kmph) towards evening/night on 28.05.2020. The predominant surface wind is likely to be coming from Southeast direction of Delhi having wind speed upto 25 kmph with partly cloudy sky, duststorm/thunderstorm accompanied with light rain and squall (speed 50-60 kmph) on 29.05.2020. The predominant surface wind is likely to be coming from Southeast direction of Delhi having wind speed upto 25 kmph with generally cloudy sky, duststorm/thunderstorm accompanied with light rain and squall (speed 50-60 kmph) on 30.05.2020.

 3. Predicted maximum mixing depth is likely to remain from 3130 m on 28.05.2020, 2180 m on 29.05.2020 and 2000 m on 30.05.2020 over Delhi. Ventilation index is likely to be 12200m²/s on 28.05.2020,17200 m²/s on 29.05.2020 and 15300 m²/s on 30.05.2020. The ventilation index lower than 6000 m²/s with average wind speed less than 10 kmph is unfavourable for dispersion of pollutants.

4. The local duststorm and dust transport from Rajasthan, Gujarat, adjoining Pakistan and Arabian Peninsula is likely to impact Delhi/NCR.

5.  Location specific AQ forecast can be seen at safar.tropmet.res.in. Detailed forecast analysis and verification can be seen at https://ews.tropmet.res.in.