Severe cold, fog set to welcome New Year: IMD

A potent combination of atmospheric forces - including the polar vortex, an Arctic blast and a western disturbance - has set the stage for severe cold conditions across northern India, with dense fog and cold day warnings issued through the New Year, the India Meteorological Department (IMD) said on Tuesday.

- Jayashree Nandi

Dense to very dense fog is likely to persist during night and morning hours over Punjab, Haryana, Chandigarh and western Uttar Pradesh on December 31, with eastern Uttar Pradesh remaining affected until January 1. Cold day to severe cold day conditions are forecast over pockets of eastern Uttar Pradesh and Bihar until Wednesday.

Under the influence of the western disturbance, heavy rain and snowfall are expected over Jammu and Kashmir and Ladakh until January 1.

Multiple meteorological phenomena are currently driving the harsh conditions. A western disturbance - manifesting as a trough in middle tropospheric westerlies - is impacting the western Himalayan region, while a subtropical westerly jet stream with ferocious core winds of 259km/h at 12.6km above mean sea level continues to influence weather patterns over Delhi.

"We can see the influence of the polar vortex which affects the jet stream, which in turn influences the path of western disturbances. This leads to cold conditions over north India. There is some influence from the Arctic blast also," said OP Sreejith, scientist and head of the climate monitoring and prediction group at IMD.