"Chennai Fog" - Times of India

CHENNAI: People driving down GST Road southwards were in for a surprise on Wednesday morning. The time was 8.10 am and the sun was bright and
shining till Tambaram. Suddenly, the road beyond Tambaram emerged as a stretch enveloped by thick fog. The lush greenery on the sides of the road and the fog provided the experience of driving along a hill station path.
It was more than an hour and a half after sunrise, but there was too little sunlight, cutting the visibility to about 50 metres. Those who had fog lamps turned the on, the others just slowed down.
"I take the road almost every day, but have not witnessed such a condition even in the earlier hours of the day. Today, even at 8.30 am I could hardly see the surroundings. The feeling is, however, heavenly, as I drove from the city into the suburbs," said Niranjan Kumar, a businessman.
Many two-wheeler riders first mistook it for pollution-induced smog. However, they soon realised that it was only fog when they felt the chilly wind on their faces as they drove through. Many motorists were seen parking their vehicles in front of the lake near SRM university to capture a picture of the mist over the lake on their mobile phones.
The met office explained the phenomenon as a combination of factors. "When the sky is clear in the night and the wind speed is slow, there can be radiation loss, leading to foggy conditions. It is a natural phenomenon. The sky over the city was partly cloudy and that was the reason there was no fog in the city. When the upper atmosphere is stable, the fog takes a longer time to clear," regional meteorological centre director S R Ramanan said.
Chennaiites had a very pleasant winter with the lowest temperature going down to around 18.3 degrees Celsius. According to the met office, weather will remain stable for a few days, with pleasant morning hours and hot afternoon hours.
"The temperature will start going up gradually till the summer arrives after March. However, the night and morning hours will remain cool for few more weeks," a meteorological department official said.