IMD predicts cold wave in Northwest India: First of the season, Delhi spared so far

A cold wave has been predicted over North Rajasthan from December 18 to 21, the IMD forecast read, while similar conditions are predicted for West Uttar Pradesh from December 19 to 21, and Gujarat from December 19 to 20. This is the first cold wave predicted for this season.

A cold wave is declared for a station in the plains when the minimum temperature is less than 10 degrees Celsius, and the minimum temperature is 4.5 degrees to 6.4 degrees less than the normal for that time of the year. A cold wave may also be declared in the plains when the minimum temperature is less than or equal to four degrees Celsius.

The IMD has not issued a cold wave forecast for Delhi yet. In Delhi, there has been no cold wave before December 20 in the last 11 years, said R K Jenamani, senior scientist, IMD. In the past ten years, the highest number of days when Delhi saw a cold wave in December was eight days in 2018. In 2019, there were three such days, and there were six in 2020. From 2014 to 2017, there was no cold wave in Delhi in December, Jenamani said.

Cold waves first hit Punjab and Haryana before Delhi, since they come from the western direction, he added.

On December 15, a western disturbance was seen as a cyclonic circulation over Jammu and surrounding areas, another western disturbance lay over Afghanistan and the neighbourhood.

Light rainfall was also on the forecast for Delhi.

There is a gap between this western disturbance and the next one which is likely around December 22 night, Jenamani said. In this gap, strong westerly or Northwesterly colder winds are likely to hit Northwest India, he said. “Cold waves depend on weather systems from the middle latitude areas… Europe or West Asia… that bring cold winds to Northwest India,” he said. Western disturbances are storms that originate in the Mediterranean region and bring winter rainfall to Northwest India.

Cold waves are usually seen from mid-December to the end of February, Jenamani said.

In Delhi, the maximum temperature recorded on Thursday was 19.8 degrees Celsius, three degrees below the normal for this time of the year. The minimum temperature on Thursday was 8.7 degrees Celsius.

On Friday, the minimum temperature in Delhi is likely to be 8 degrees Celsius, while the maximum could settle at 20 degrees Celsius. From December 18 to 21, the minimum temperature is likely to be 6 degrees Celsius, going by the IMD forecast.