According to the National Weather Forecasting Centre of the India Meteorological Department (IMD):Wind Pattern and Ventilation Index Forecast .
Air mass inflow forecast in Delhi along with predicted ventilation coefficient and weather forecast is as follows:
The air quality over Delhi-NCR is likely to improve marginally but remain in Poor to Moderate category on 13.04.2021. The predominant pollutant is PM10 because of higher dust concentration. The air quality is likely to remain in Moderate category on 14.04.2021 and 15.04.2021. The Outlook for subsequent 5 Days: The air quality is likely to remain largely in Moderate category.The predominant surface wind is likely to be coming from Northeast directions of Delhi with wind speed 08-15 kmph and mainly clear sky on 13.04.2021. The predominant surface wind is likely to be coming from West directions of Delhi with wind speed 06- 18 kmph and partly cloudy sky on 14.04.2021. The predominant surface wind is likely to be coming from Northwest directions of Delhi with wind speed 05-18 kmph and partly cloudy sky on 15.04.2021.
Predicted maximum mixing depth is likely to be approx 4800 m on 13.04.2021, 5300 m on 14.04.2021 and 5000 m on 15.04.2021 over Delhi. Maximum Ventilation index is likely to be approx 42000 m2/s on 13.04.2021, 36000 m2/s on 14.04.2021and 31500 m2/s on 15.04.2021.The ventilation index lower than 6000 m2/s with average wind speed less than 10 kmph is unfavourable for dispersion of pollutants.
Higher dust concentration is likely over parts of Rajasthan, Gujarat, Delhi, MP and UP. Marginal effect of transported and local dust over Delhi/NCR is likely today.