Delhi witnesses first spell of dense fog; IMD issues alert for next 5 days

Delhi witnessed its first spell of the fog of the season on Monday (December 19) as thick layers of fog descended across the Indo-Gangetic plains. Visibility in the capital city was reduced to 150 meters, affecting road and rail traffic movement.

The temperature will remain the same in the coming days and the national capital will witness shallow fog this week, the weather department predicted.

Speaking to The Federal, RK Jenamani, scientist, IMD said four factors – humidity levels, low temperature, wind speed and pollutants – play a role in the formation of fog near the surface. The senior scientist termed fog as a meteorological event with high spatial variability. He said the current spell of fog may last for three to four days in Punjab, but for a shorter duration in Delhi.

Mukut Singh, senior meteorologist, Skymet, said a dense layer of fog started spreading from Punjab, and made its way to eastern Uttar Pradesh, via Haryana, Delhi and western Uttar Pradesh. He said while dense fog was not forecast for Delhi until the end of the December, meteorological conditions changed within a matter of hours, becoming conducive for fog formation.

Explaining the sudden occurrence of thick fog in the national capital, the meteorologist said Delhi had all favourable conditions – calm winds and low temperature as fog needs adequate moisture, calm winds and low temperatures to thicken. Moisture from the northern plains may have contributed to the density of the fog.

“Isolated pockets over Punjab, Himachal Pradesh, Northern Rajasthan and Haryana may witness cold wave conditions,” Singh warned.

Due to dry north-north-westerly winds from the Himalayas, cold wave conditions are likely to continue over Himachal Pradesh, Punjab, Haryana, and north Rajasthan during the next four to five days, weather department said in its circular.

Earlier in the day, satellite images released by Indian Meteorological Department (IMD) showed a thick layer of fog extending from Punjab to east Uttar Pradesh across Haryana and Delhi.

Also read: IMD predicts dense fog over north-west India for next 5 days

The IMD has predicted dense to very dense fog over the plains in northwest India over the next five days.

Meanwhile, Delhi also witnessed an increase in Air Quality Index (AQI). The AQI in Delhi’s Anand Vihar area was recorded at 450 which falls under the severe category.

Delhi recorded the coldest night of the season for the fourth continuous day on Sunday when the lowest temperature in the city dipped to 6 degrees Celsius, two degrees below normal.