At 18 hours, Delhi-NCR sees season's longest fog spell

GURUGRAM: At almost 18 hours, Delhi-NCR witnessed its longest spell of fog this season. The fog cover lasted from 7pm on Monday till 1pm the next day.
The thick blanket of fog reduced visibility to just 50m, affecting movement of flights, trains and vehicles on the road. In Gurugram, though, the fog started clearing out by 11am, giving way to sunshine. It, however, remained windy through the day.
The minimum and maximum temperatures rose marginally, a day after both plunged to the season's lowest on Monday. The minimum temperature was 6.1 degrees Celsius, which is near the normal for this time of the year, against 5.4 degrees Celsius the previous day. The daytime temperature climbed by over 5 degrees to 17.3 degrees Celsius, against Monday's 11.7 degrees Celsius. It was still three notches below the season's normal. The city recorded the season's first 'severe cold day' on Monday and a 'cold day' on Sunday.
According to the IMD, the minimum temperature is likely to rise by 2-3 degrees during the next three days due to the impact of a western disturbance on the western Himalayan region, while moderate to dense fog is likely to continue during the next 4-5 days.
"Due to high moisture, dense to very dense fog has been witnessed over many parts of Haryana, including Gurugram. Moderate to dense fog is likely to continue for the next few days. Due to the western disturbance, winds have picked up pace during the daytime. As a result, fog is clearing out soon, allowing sunlight to reach the surface. This is leading to an increase in temperature. There will be a gradual rise in the minimum temperature by 2-3 degrees over the next three days," an IMD official said.
According to the IMD's forecast, it will be mostly sunny on Wednesday with moderate to dense fog in the morning hours. The minimum and maximum temperatures are expected to hover around 7 and 15 degrees Celsius, respectively.
Meanwhile, the city's air quality improved slightly due to a rise in wind speed but remained in the 'poor' category. The overall air quality index (AQI) was 252, compared to 281 on Monday.
In Delhi, there was little respite for residents on Tuesday with some pockets of the city shivering under 'cold wave' as well as 'cold day' conditions for the third day at a stretch. The maximum temperature at Safdarjung, the city's base station, was 17.2°C, three notches below normal and the minimum at 5.6°C, a degree below normal - and lower than that of Dharamsala (6.2°C) and Nainital (7.2°C). Ayanagar, at 4°C, was the coldest area in the capital.
Visibility at the IGI Airport and adjacent areas fell below 50 metres in the morning, which delayed several flights. Two in-bound flights had to be diverted to Jaipur. Fifteen trains to and from Delhi were running late while two had to be rescheduled.
Dense to very dense fog prevailed in some parts of NCR, Punjab, western Uttar Pradesh and north Rajasthan as well. While the harsh winter conditions along with dense fog will persist in Delhi on Wednesday, the city is likely to get respite from 'cold day', 'cold wave' and dense fog on December 29 and December 30 due to the impact of a western disturbance. The disturbance is expected to cause snowfall in Himachal and J&K along with a drizzle in north Punjab, says the weather department. However, the winds will turn north-westerly again, causing 'cold wave' conditions and dense fog in the capital on December 31 and January 1. "We can't, though, predict the intensity of the fog as yet," said RK Jenamani, senior weather scientist, IMD.
Meanwhile, the consistent fog period that kept visibility below 1,000m in the city spanned 7pm Monday to 1pm Tuesday. Between 11.30pm Monday and 9.30am Tuesday, the visibility was below 200 metres.
"This qualified for 'CAT3A fog' at the airport. The visibility was least between 1.30 am to 9.30pm. The 'low visibility procedure' was active at the airport from 7pm Monday to 11am Tuesday," said Jenamani.
The maximum temperature at Palam was 15.5°C, the 'lowest maximum' in the city, and five degrees below normal, which qualifies for the 'cold day' criterion.
The air quality remained 'very poor' with the AQI at 339 on a scale of 0 to 500, against 331 a day earlier.
(With inputs from
Kushagra Dixit in Delhi)