Snowfall and rain over North-West India have been comparably less despite the winter having arrived early this year, according to leading scientists and meteorologists.

Temperatures are expected to fall further over the region as the season enters the months of January and February, Climate Trends, a strategic communications initiative on climate ambition and low carbon development pathways, said.

GP Sharma, President-Meteorology and Climate Change at leading private forecaster Skymet Weather, said that North-West India is now gearing-up for a prolonged winter season ahead, along with some record low temperatures across the Indo-Gangetic plains.

“What brings cold to the region is the north-westerly winds which brings in the chill from higher latitudes (farther to the North and North-West across our international border) to the Indo-Gangetic plains,” points out Sharma.

Icy-cold winds

Passage of back-to-back western disturbances tend to change the wind direction from cold north-westerlies to warm and humid easterlies. But with La Niña in place, we expect less amount of winter rains and thus icy cold winds would blow into North-West India bringing down the mercury.

“As we enter into the thick of winter, a series of cold waves could engulf both the hills as well as plains of North-West India. In line with La Nina season characteristics, minimum temperatures have already started plunging into the lower single digits, much below average normal temperatures.”

Meteorologists predict minimum temperatures may dip close to freezing point in the coming days. A cold wave is declared when the minimum temperature across the plains settles below 10 degrees Celsius and is 4-6 degrees below the normal. Meanwhile, the criteria for the hills is 0 degrees Celsius.

A study published by the International Journal of Climatology says that an El Niño leads to enhanced winter precipitation over North-West India and vice-versa (during La Niña). During the warm phase, western disturbances intensify due to strong north-easterly flows from Siberia.

Record low temperatures

La Niña has the potential to affect India’s winter as it influences the wind pattern and speed, says Raghu Murtugudde, Professor of Atmospheric and Oceanic Science and Earth System Science at the University of Maryland, and currently Visiting Professor at IIT Bombay.

“ La Niña brings cold air from Siberia and South China over the Indian sub-continent that interacts with the tropical heating. The cold air associated with the resulting north-south trough tends to extend much further south into India,” explained Murtugudde.

AP Dimri, School of Environmental Science, Jawaharlal Nehru University, said this translates into intermittent waves of extremely cold weather throughout the season. Also, cyclonic circulations would be more marked and would have the probability to penetrate deeper into North-West India.

“With this, we can expect a series of intense cold waves, record low temperatures and chilly winds," he added.