Context: The India Meteorological Department (IMD) has forecast a warm winter season across the country, saying minimum temperature could remain higher than normal.                                                     

El Nino, Other Factors to Cause Warm Winter

• El Nino Peak: The El Nino condition is inching to its peak. As per the recent observations, the Nino 3.4 region remained 2.4 degrees Celsius above the threshold, as per Indian Meteorological observations.
• Record-Breaking Temperature Trends in 2023: Since 1901 in India, 2023 is on its way to becoming the warmest year ever recorded on Earth with February, August, and November being the warmest months. 
• Cyclone Michaung’s Influence on Temperature: The soon-to-develop Cyclone Michaung will also cause cloudiness and the minimum temperature over south peninsular India and eastern coastal India will remain above normal during the upcoming days.

What is El Nino?

• El Nino,  meaning “the little boy” in Spanish refers to an abnormal warming of surface waters in the equatorial Pacific Ocean. 
• Scientists in the 1920s first noticed it. It is known to suppress monsoon rainfall. 
• It occurs on average every two to seven years, and episodes usually last nine to 12 months.  
• Formation: 
  • It forms when the trade winds blowing east-to-west along the equatorial Pacific slow down or reverse as air pressure changes, although scientists are not entirely sure what kicks off the cycle.
  • Because the trade winds affect the sun-warmed surface waters, a weakening causes these warm western Pacific waters to slosh back into the colder central and eastern Pacific basins.
• Impacts: 
  • El Niño events are typically associated with increased rainfall in parts of southern South America, the southern United States, the Horn of Africa, and central Asia.
  • In contrast, El Niño can also cause severe droughts in Australia, Indonesia, and southern Asia.

What are the reasons for Warm Winter?

• Factors responsible for Anticipated Warm Winter Weather: 
  • Due to large-scale features like El Nino, in addition to the regional factors like western disturbances and the upcoming cyclone developing in the Bay of Bengal, there are chances of higher-than-normal minimum temperatures, making it a warm winter season over the country.
  • Fewer and less intense cold waves could warm the December- February period.
  • Cloudy conditions caused by western disturbances push the minimum temperature.
    • For Example: In November, five western disturbances crossed the northern India region. Two of these caused widespread rainfall over Rajasthan, Madhya Pradesh, Gujarat, and Maharashtra when interacting with easterly winds.

Also Read: Western Disturbances

News Source: The Indian Express