New Delhi: The India Meteorological Department (IMD) on Monday (November 22, 2021) warned that a cold wave is likely over parts of Haryana Punjab and northern Rajasthan in the next two days. The weather office said that this will be the first cold wave this season.
According to a report in the Hindustan Times, “Minimum temperatures are likely to dip in Delhi but a cold wave is not likely. Cold wave may be recorded in Haryana and Punjab,” said RK Jenamani.
A cold wave is declared by the weather office when the minimum temperature drops below 10 degrees Celsius or is 4.5 degrees lower than the season’s normal for two straight days.
Earlier, on November 17, the minimum temperature in Delhi fell to 9.6 degrees and 9.8 degrees on Sunday, which is 3 degrees below normal on both days, while, on Monday, the minimum temperature was 11.4 degrees. On the other hand, Haryana’s Hisar recorded 7.2 degrees on Monday, 4 degrees below normal.
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The head of climate research and services at IMD Pune, DS Pai explained, “There are two ways by which the temperature falls. One is a clear sky, which leads to the warmth radiating back quickly from the surface. It’s called radiational cooling. There are clear skies over northwest India now.”
“The other reason for cold setting in is that northwesterly cold and dry winds are blowing over the region from the Himalayas. There is a low-pressure area over the Arabian Sea which also indirectly helps in the incursion of northwesterly winds over the entire northwestern region. This happens during winter. Consecutive low-pressure areas have formed over the Arabian Sea,” he was further quoted as saying in the report.
Additionally, a senior scientist at IMD, RK Jenamani said, “We are expecting cold air incursion. In Delhi, there may not be a cold wave condition, but minimum temperatures will fall to about 8 to 9 degrees, around 3 to 4 degrees below normal.”
“In rural pockets, cold wave conditions are likely to set in,” he added.
The weather officials also noted that weak La Niña conditions are prevailing over the equatorial Pacific Ocean currently. The weather office stated that La Niña conditions are likely to strengthen and peak to moderate conditions during winter.
“La Nina conditions are associated with colder winters over northwest India,” said Pai.
It may be noted that, according to the National Oceanic and Atmospheric Administration (NOAA), El Niño and the Southern Oscillation (ENSO) is a periodic fluctuation in sea surface temperature and the air pressure of the overlying atmosphere across the equatorial Pacific Ocean.
