Northern India is bracing for harsh winter conditions as a combination of meteorological phenomena—including a polar vortex, an Arctic blast, and a western disturbance—has created an environment conducive to severe cold and dense fog. The India Meteorological Department (IMD) on Tuesday issued warnings of dense to very dense fog and cold day conditions through the New Year, with pockets of severe cold expected across several states.

Dense Fog Alerts

The IMD has predicted that dense to very dense fog will persist during night and morning hours over Punjab, Haryana, Chandigarh, and western Uttar Pradesh on December 31. Eastern Uttar Pradesh is expected to remain affected by dense fog until January 1. Visibility in these areas is likely to drop below 50 metres in several locations, causing potential disruptions to road, rail, and air travel. Isolated pockets in Himachal Pradesh, Uttarakhand, and eastern Madhya Pradesh may also experience dense fog with visibility between 50 and 199 metres.

The persistent fog, coupled with low daytime temperatures, poses unique public health risks. The IMD advisory warns of increased susceptibility to flu, nosebleeds, and other cold-related illnesses. Citizens are advised not to ignore shivering, as it may indicate the body is losing heat. Prolonged exposure can result in frostbite, with symptoms including pale, hard, and numb skin, eventually progressing to black blisters on extremities such as fingers, toes, nose, and earlobes. Immediate medical attention is necessary in severe cases.

Cold Day and Severe Cold Day Conditions

The IMD has forecast cold day conditions over parts of eastern Uttar Pradesh and Bihar, continuing through January 1. A cold day is declared when temperatures fall below 10°C and the maximum temperature is 4.5°C to 6.4°C below normal. A severe cold day is indicated when the departure exceeds 6.5°C. Unlike conventional cold waves that primarily affect nighttime temperatures, cold day conditions reduce daytime warmth, posing additional risks for those working outdoors or commuting.

Meteorological Factors Driving the Cold

Several meteorological systems are contributing to the extreme conditions. A western disturbance, appearing as a trough in the middle tropospheric westerlies, is currently affecting the western Himalayan region. This is accompanied by a subtropical westerly jet stream with core winds reaching 259 km/h at an altitude of 12.6 km, influencing weather patterns over Delhi and surrounding areas.

IMD scientist OP Sreejith explained that the polar vortex is impacting the jet stream, which in turn affects the trajectory of western disturbances. The combined effect, along with an Arctic blast, has intensified cold conditions across the northern plains. Additional weather systems, including a trough in easterlies over the southeast Bay of Bengal and upper air cyclonic circulations over northern Kerala and northeast Assam, are adding complexity to the prevailing patterns.

Precipitation and Snowfall

The IMD has also forecast heavy rain and snowfall over Jammu and Kashmir and Ladakh until January 1. Isolated to scattered light or moderate rainfall and snowfall are expected over Himachal Pradesh and Uttarakhand until January 2. Meanwhile, Punjab, Haryana, Chandigarh, and parts of western Rajasthan may witness isolated light to moderate rainfall on Wednesday and Thursday.

Temperature Trends

Minimum temperatures have already dropped below 4°C at several locations in Kashmir and Ladakh, with readings between 4°C and 10°C across parts of Uttarakhand, Madhya Pradesh, northern Rajasthan, Odisha, Uttar Pradesh, Marathwada, Gangetic West Bengal, and Chhattisgarh. Certain regions, including eastern Madhya Pradesh, northern interior Odisha, Chhattisgarh, Gangetic West Bengal, Jharkhand, and northern interior Karnataka, have recorded temperature departures significantly below normal, ranging from minus 5°C to minus 3.1°C.

The lowest minimum temperature in the country’s plains was recorded at Nowgong in eastern Madhya Pradesh, registering just 3°C. Such low temperatures, combined with dense fog, are expected to impact agriculture, livestock, water supply, transport, and power sectors, creating potential challenges for daily life and economic activity.

Public Advisory

Authorities are urging citizens to exercise caution during this period. Precautions include limiting exposure to extreme cold, wearing adequate protective clothing, and monitoring children and elderly individuals who are particularly vulnerable. Commuters are advised to factor in potential travel delays caused by low visibility, while farmers and livestock owners should take measures to protect crops and animals from frost and cold damage.

With northern India entering the New Year under these severe weather conditions, the IMD’s warnings serve as a crucial reminder of the need for preparedness and caution. Residents are encouraged to follow official advisories closely and ensure that vulnerable populations are safeguarded against the impacts of cold and fog.