Winter Fog Experiment Forecast (2020-21):
WIFEX Forecast based on 00Z 26th Jan 2021.
1. WRF-(4km) 5-member physics ensemble indicates fog over Delhi and IGI airport.
2. 21 member ensemble probability forecast for Delhi shows above 80% probability of fog in CAT 3A category during the early morning hours.
IMD FDP Bulletin on fog forecast for 27th January 2021:
Considering low level winds, Relative humidity, temperature inversion between 1000-925 hPa & minimum temperature and guidance from different models i.e. NCUM, GFS & ECMWF, current spell of Dense to Very Dense Fog in isolated/some pockets likely to prevail over Punjab and Uttar Pradesh during next 2 days and decrease thereafter becoming isolated Dense Fog over these areas.
Under the influence of dense fog/low cloud conditions, Severe Cold Day conditions are very likely in some pockets over Uttar Pradesh during next 2 days and significant decrease thereafter.
Isolated Cold Wave/Cold Day and Dense to Very Dense Fog conditions very likely over Madhya Pradesh during next 2-3 days.
Isolated Dense Fog conditions are very likely over Bihar, Sub-Himalayan West Bengal, Assam & Meghalaya and Nagaland, Manipur, Mizoram & Tripura during next 3 days.
Visibility Range
VISIBILITY: Below 50 M
VISIBILITY: FROM 50M TO 174M
VISIBILITY: FROM 175M TO 299M
VISIBILITY: FROM 300M TO 549M
VISIBILITY: 500M AND ABOVE
Air Quality Index Range
AQI: Good (0 - 50)
Air quality is considered satisfactory, and air pollution poses little or no risk.
AQI: Satisfactory (51 - 100)
Air quality is considered satisfactory, and air pollution poses little or no risk.
AQI: Moderate (101 - 200)
Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.
AQI: Poor for Sensitive Groups (201 - 300)
Although general public is not likely to be affected at this AQI range, people with lung disease, older adults and children are at a greater risk from exposure to ozone, whereas persons with heart and lung disease, older adults and children are at greater risk from the presence of particles in the air.
AQI: Very Poor (301 - 400)
Health alert: everyone may experience more serious health effects.
AQI: Severe (401 - 500)
Health warnings of emergency conditions. The entire population is more likely to be affected.
AQI: Good (0 - 50)
Air quality is considered satisfactory, and air pollution poses little or no risk.
AQI: Satisfactory (51 - 100)
Air quality is considered satisfactory, and air pollution poses little or no risk.
AQI: Moderate (101 - 200)
Air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.
AQI: Poor for Sensitive Groups (201 - 300)
Although general public is not likely to be affected at this AQI range, people with lung disease, older adults and children are at a greater risk from exposure to ozone, whereas persons with heart and lung disease, older adults and children are at greater risk from the presence of particles in the air.
AQI: Very Poor (301 - 400)
Health alert: everyone may experience more serious health effects.
AQI: Severe (401 - 500)
Health warnings of emergency conditions. The entire population is more likely to be affected.