The minimum (night) temperatures across almost the entire northern half of the country (North-West, East and Central India) may dip by 3-4 degree Celsius towards the weekend, according to an outlook by the India Meteorological Department (IMD). This will come about as a fresh western disturbance about to enter the country via the North-West border moves away gradually to the East-North-East and cedes space to cold winds from farther North-West. Weather-making western disturbances frequenting the North-West are known to modulate regional weather from wet and thundery spells to cold waves.
The IMD located the disturbance over Afghanistan and neighbourhood this (Tuesday) morning. It is a suitably endowed (deep and intense) system and can induce the formation of an offspring cyclonic circulation up front over West Rajasthan during the rest of the day. An induced circulation travels ahead of the parent western disturbance, and can ratchet up weather in the form of snow in the hills and thunderstorms along the plains.
Rain, snow forecast for North
The IMD expects the system to set off light to moderate to fairly-widespread to widespread rain/snow over the hills during the next two days with the possibility of isolated heavy falls over Jammu & Kashmir and Himachal Pradesh today and over Uttarakhand both today and tomorrow (Tuesday and Wednesday). Early this morning, lingering moisture in the air caused dense fog to envelope isolated places across Bengal, Sikkim and Bihar while it was moderate over Assam, Meghalaya, Himachal Pradesh, East Uttar Pradesh, Bihar and Tripura.
Scattered to fairly widespread rain is forecast over Punjab, Haryana, Chandigarh and Delhi while it will be isolated to scattered over North Rajasthan and Uttar Pradesh today and tomorrow (Tuesday and Wednesday) with the possibility of isolated heavy falls over North-West Uttar Pradesh. Isolated thunderstorm and lightning accompanied by hailstorm is likely over Jammu & Kashmir and Himachal Pradesh today, and over Uttarakhand, Punjab, Haryana, Chandigarh, Delhi and Uttar Pradesh both today and tomorrow.
An extended forecast valid from January 12 to 14 indicated the possibility of scattered to fairly widespread rain/snow over the hills of North-West. Isolated to scattered rainfall is likely over parts of Central, East and North-East India and over the South Peninsula (including Tamil Nadu).