Thunderstorm accompanied with lightning at isolated places is very likely over Andaman and Nicobar Islands.
The cold spell is likely due to two different western disturbances that prevail over the region. As per IMD, isolated to scattered light rainfall and snowfall is very likely over Himachal Pradesh and Uttarakhand on February 15 and 16.
Moreover, there is prediction by the IMD of shallow to moderate fog conditions during the night and morning hours in parts of Punjab and Haryana during the next 48 hours.

Weather News Forecast for Tomorrow (February 16)
As per the IMD, a fresh spell of rainfall is likely for parts of India including Andaman and Nicobar Islands, Tamil Nadu, Kerala and the Lakshadweep Islands. This is due to the influence of the Western Disturbances.
Also, there will be shallow to moderate fog conditions during night. Besides, fog during the morning hours is very likely in northern parts of Punjab, Haryana and Uttar Pradesh during the next 48 hours.
Weather News for South India
Isolated rainfall over Tamil Nadu, Kerala and the Lakshadweep Islands over the next 3 to 4 days is very likely. This is due to the influence of northeasterly winds flowing in the lower troposphere blowing over coastal Tamil Nadu.

Rainfall is also expected over the plains of northwest India from February 17 to 20.
In addition, another western disturbance from February 17-20 will result in lead to scattered to fairly widespread light rainfall/snowfall over the western Himalayan region and isolated or scattered rain over the northwest India.
Furthermore, the IMD has predicted a gradual rise in minimum temperatures by 2 to 4 degrees Celsius over most parts of northwest India during the next four days.
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