Updated: December 15, 2020 4:14:38 pm
A misty winter morning in New Delhi. (Express photo: Amit Mehra)
The minimum or nighttime temperature in New Delhi fell to 4.1 degrees Celsius on Tuesday, the lowest during the season this year. The drop was five degrees below normal temperature for this time of year, according to the Indian Meteorological Department (IMD).
The meteorological department has predicted that mercury will fall further over the next three days, both day and night.
What is causing the drop in temperature in Delhi?
There has been a significant amount of snowfall in recent days in the states that fall in the western Himalayas (Jammu and Kashmir, Himachal Pradesh and Uttarakhand) under the influence of a western unrest.
“In winters, whenever an active western disturbance passes through the western Himalayan region, it causes a drop in temperatures in northwestern India,” said Kuldeep Srivastava, head of IMD’s regional weather forecast center.
A western disturbance, labeled an extratropical storm originating from the Mediterranean, is a low pressure area that brings sudden rains, snow and fog in northwestern India.
“Snowfall in the western Himalayas means cold northwesterly winds blowing over Delhi from the direction of this high altitude area and clearing the cloud cover as western unrest passes, leading to a drop in temperatures.” Srivastava said. 📣 Follow Express explained on Telegram
A rapid drop in the minimum temperature in Delhi from 14.4 degrees Celsius was observed on December 12, when the city witnessed light rain, to 4.1 degrees on Tuesday.
The lack of cloud cover also leads to increased radiation from the Earth’s surface to the atmosphere at night, which also cools the ground, Srivastava said.
Also, under the influence of an active La Niña weather pattern, temperatures around the world have dropped, he added.
The high or daytime temperature has also dropped in Delhi from 29 degrees Celsius on December 10 to 19.4 degrees Celsius on Monday.
Weather forecast for Delhi: what to expect in the coming days
IMD has forecast cold days and cold wave conditions in some parts of the city for the next three days.
A cold day is when the maximum temperature drops 4.5 degrees Celsius below the normal temperature, which has been established based on 30-year climatological data between 1981 and 2010.
Cold wave is when the minimum temperature drops to 10 degrees Celsius or less and the deviation from normal temperature is 4.5 degrees Celsius or less.
Until December 19, the maximum temperature is forecast to be between 18 and 19 degrees Celsius while the minimum temperature is forecast between 4 and 5 degrees Celsius.
© The Indian Express (P) Ltd
.
