Dense fog disrupts 100 flights, Delhi shivers as minimum temperature drops

On Thursday, the minimum temperature in the Capital also dropped to 5.8 degrees Celsius (°C) – two degrees below normal -- from 8.2°C on Wednesday

Around 100 flights were delayed as dense fog engulfed the runways at Delhi’s Indira Gandhi International (IGI) airport, dropping visibility to around 50-100 metres between 4.30am and 9.30am on Thursday. Officials, however, said no flights were cancelled or diverted during the day.

IMD scientist RK Jenamani said this was the first dense fog spell of the season witnessed at Safdarjung, with visibility remaining below 200 metres between 7am and 9.30am. At Palam, the impact lasted for around five hours, he said. (Amal KS/HT Photo)

On Thursday, the minimum temperature in the Capital also dropped to 5.8 degrees Celsius (°C) – two degrees below normal -- from 8.2°C on Wednesday.

India Meteorological Department (IMD) has forecast the minimum temperature to hover around 6°C for the next two days, amid a likelihood of moderate to dense fog.

The IMD classifies fog as ‘shallow’ when visibility is between 500 and 1000 metres, ‘moderate’ when it is between 200 and 500 metres and ‘dense’ when it drops below 200 metres.

IMD scientist RK Jenamani said this was the first dense fog spell of the season witnessed at Safdarjung, with visibility remaining below 200 metres between 7am and 9.30am. At Palam, the impact lasted for around five hours, he said.

“CAT-III procedures (precision steps to help flights land) were initiated at the Delhi airport as visibility ranged between 50 and 100 metres since 4.30am. There was a slight improvement only after 9.30am,” he said, adding that low wind speed and sufficient moisture in the air were aiding fog formation.

“There is a good chance we see dense fog over the next two days too. This is the first such spell where we are regularly seeing moderate to dense fog,” he said.

An airport official said that despite low visibility, flight operations remained smooth. “Like Tuesday’s spell, low visibility procedures were in place, but no diversions or cancellations were reported on account of the adverse weather. Slight delays were recorded till the afternoon,” the official said.

Meanwhile, Delhi’s air quality has deteriorated in the last 24 hours, touching the ‘very poor’ category on Thursday. According to the Central Pollution Control Board’s daily 4pm bulletin, Delhi’s overall air quality index (AQI) was 321, up from Wednesday’s 191 (moderate).

The Centre-run System of Air Quality and Weather Forecasting And Research (Safar) has predicted further deterioration in air quality, owing to low temperatures and high moisture, in the next three days.

“Wind speed has dropped and there is enough moisture in the air to trap pollutants. Low temperatures are also making it difficult for pollutants to disperse...The air quality will deteriorate further in the next few days, but is expected to remain within the ‘very poor’ range,” said Gufran Beig, founder project director, Safar.