The residents of the Delhi-NCR on 23 May opened their eyes to a ‘mysterious fog’ that has led to the decreased visibility due to the dust particles.
The light fog was seen in the national capital in the early hours around ITO, Akshardham and Delhi Noida Direct (DND) flyway. The dust particles were also witnessed near the Rajpath Area.
“Due to dust raising winds, visibility reduced in Delhi. Safdarjung reported 0500 m visibility at 0830 hrs,” the India Meteorological Department (IMD) said.
The IMD says the sky in Delhi is likely to remain cloudy on Sunday with a possibility of thunder and lightning.
“The maximum and minimum temperature are likely to hover around 37 and 20℃, respectively,” the IMD predicted.
The national capital experienced pleasant weather as the skies remained partly cloudy and the maximum temperature settled five notches below the season’s average at 35.1℃, the IMD said.
The city has received light to moderate rainfall during the last three days due to a western disturbance.
Earlier on 22 May, the skies remained partly cloudy and the maximum temperature settled five notches below the season’s average at 35.1℃ in the national capital.
Saturday’s minimum temperature was recorded at 18℃, nine degrees below normal.
Delhi had recorded a maximum temperature of 23.8℃ on 19 May, 16 degrees below the normal and the lowest in the month of May since 1951.
Meanwhile, Delhi’s Air quality index (AQI), as per the SAFAR app at 9 AM on 23 May, was in the ‘satisfactory’ category and registered at 66.
This is to be noted that an AQI between zero and 50 is considered ‘good’, 51 and 100 ‘satisfactory’, 101 and 200 ‘moderate’, 201 and 300 ‘poor’, 301 and 400 ‘very poor’ and 401 and 500 ‘severe’.
Rainfall recorded below 15 mm is considered ‘light’, between 15 mm and 64.5 mm is ‘moderate’, 64.5 mm and 115.5 mm ‘heavy’, and between 115.6 mm and 204.4 is ‘very heavy’. Anything above 204.4 mm is considered ‘extremely heavy’ rainfall.
Delhi fog explained
Fog is a phenomenon of small droplets remaining suspended in the air. Fog develops normally during late evening, night or early morning hours of the day, severely affecting visibility. Poor visibility, falling to less than a kilometre disrupts the smooth flow of vehicular and air traffic. Road accidents, delays in flight take-offs and landings are linked to poor visibility caused by fog. Foggy conditions prevail over the plains of north India during the winter season and can prolong for days and sometimes even for weeks.
Clear sky conditions accompanied by calm winds during the day allowed the fog to persist for longer than normal duration.
The Punjab-Haryana-Delhi belt is infamous for possessing a high concentration of sources causing air pollution, but this season, the pollutants had little role to play with respect to fog, meteorologists say.
Meanwhile, the national capital was seen engulfed in dust today, which led to a decreased visibility. Visuals from Delhi showed dust in the environment.
Yesterday, the convergence of a cyclone and a western disturbance caused record-breaking heavy rainfall in Delhi on Wednesday. The IMD recorded 119.3 mm of rain in the capital on Wednesday, which is the highest-ever 24 h mark for the month of May.
It happened when Cyclone Tauktae, one of the strongest cyclones to have been recorded in the Arabian Sea, weakened and its remnants moved in the north-northeast direction from the Gujarat coast towards Delhi.
Simultaneously, a western disturbance, which is a weather pattern associated with non-monsoon showers, was moving towards Delhi from the western Himalayan region.
The convergence of these two phenomena caused widespread rain in the capital, which caused waterlogging in some parts of the city and led to a road cave-in near Najafgarh in southwest Delhi.
Finally, the fact that it rained heavily in May, which is generally a dry month ― the region has not recorded more than 27 mm of rain in total since at least 2011 except in 2014 when it touched 100.2 mm ― left droplets of moisture suspended in the air due to the higher temperature in drier conditions, unlike the conditions moisture would be subjected to during monsoon.
The average amount of rainfall expected in May in the capital city is 31.5 mm.
It is also rare for a cyclone to make its impact felt in Delhi, and more so at the same time when a western disturbance is active. The aggregate impact of the factors above caused the fog (suspension of water droplets in the air at a low altitude) this morning.