“Wind-chill factor” explains the unusual cold in Bangalore

“Wind-chill factor” explains the unusual cold in Bangalore

Staff Reporter

Bangalore: Even as Bangaloreans struggle to keep warm, wrap themselves up in extra layers of woollens or just curl up under quilts, the city’s meteorological centre springs a surprise: the minimum was as high as 18 degrees Celsius on Tuesday morning. Surely, the thermometer was lying, one may think, for it certainly feels a lot colder than that. The truth lies in the “wind chill factor.” With wind speeds up to 46 kmph, no wonder the city felt much colder than it was.

Our warm blooded bodies, it turns out, gauge our environment far more keenly than the technologies we so depend on. “Our skin interprets weather differently. Minimum temperatures are not the only indicators of cold weather for us. We experience the combined effects of temperature, humidity and the wind-chill factor,” says G.S Bhat, professor at the Centre for Atmospheric and Oceanic Studies (CAOS) in the Indian Institute of Science. “These factors can make us feel several degrees colder than what the thermometer tells us.”

These strong winds blowing over Bangalore since Sunday have been unmistakably picking up speed, with window panes rattling louder and trees teetering at a greater incline every day. From a fairly reasonable 28 kmph on Saturday, it became a gusty 40 kmph on Sunday, 44 kmph on Monday and rose to a strong 46 kmph on Tuesday. The winds are stronger still at the airport, going up to 48 kmph on Monday.

Although the temperatures over these four days have hovered between 16 and 18 degrees Celsius, the winds, which have also been bringing in copious moisture, have added to the chill factor, according to G. Vijayaraghavan, director of the meteorological centre. “These strong winds, accompanied by light rain, in the city have their origins in the Bay of Bengal, where a trough of low pressure is forming,” he adds.

“If the trough turns into a depression, we can expect more rain in Bangalore in the next two days,” he says. “There is an upper air cyclonic circulation that has developed over the Bay of Bengal, and it has a likelihood of developing into a low pressure.”