Latest forecasts from WMO Global Producing Centres of Long-Range Forecasts indicate a 55 per cent likelihood of a transition from the current neutral conditions to La Nina conditions during December 2024 to February 2025.

As of the end of November 2024, oceanic and atmospheric observations continue to reflect ENSO-neutral conditions which have persisted since May. Sea surface temperatures are slightly below average over much of the central to eastern equatorial Pacific.

What is El Nino and La Nina?

• El Nino and La Nina events are a natural part of the global climate system. They occur when the Pacific Ocean and the atmosphere above it change from their neutral (‘normal’) state for several seasons.

• It occurs on average every two to seven years, and typically lasts nine to 12 months. 

• El Nino, which is the warming of the waters in the Pacific Ocean near South America, is generally associated with the weakening of monsoon winds and dry weather in India.

• It influences weather and storm patterns in different parts of the world. But it takes place in the context of a climate being changed by human activities. 

• It is associated with increased rainfall in the Horn of Africa and the southern US, and unusually dry and warm conditions in Southeast Asia, Australia and southern Africa. 

• La Nina, which is the opposite of El Nino, typically brings good rainfall during the monsoon season.

• These changes in the Pacific Ocean and its overlying atmosphere occur in a cycle known as the El Nino–Southern Oscillation (ENSO). 

• The term ‘El Nino’ translates from Spanish as ‘the boy-child’. Peruvian fishermen originally used the term to describe the appearance, around Christmas, of a warm ocean current off the South American coast. It is now the commonly accepted term to describe the warming of the central and eastern tropical Pacific Ocean. ‘La Nina’ translates as ‘girl-child’ and is the opposite ENSO phase to El Nino.

• However, naturally occurring climate events such as La Nina and El Nino events are taking place in the broader context of human-induced climate change, which is increasing global temperatures, exacerbating extreme weather and climate, and impacting seasonal rainfall and temperature patterns.

World Meteorological Organisation (WMO)

• The World Meteorological Organisation (WMO) is a specialised agency of the United Nations. 

• It is the UN system’s authoritative voice on the state and behaviour of the Earth’s atmosphere, its interaction with the oceans, the climate it produces and the resulting distribution of water resources.

• The WMO has 193 Members, including 187 Member States and 6 territories, maintaining their own meteorological services.

• It originated from the International Meteorological Organisation (IMO), which was founded in 1873.

• Established in 1950, WMO became the specialised agency of the UN in 1951 for meteorology (weather and climate), operational hydrology and related geophysical sciences. 

• WMO facilitates the free and unrestricted exchange of data and information, products and services in real or near-real time on matters relating to safety and security of society, economic welfare and the protection of the environment. It contributes to policy formulation in these areas at national and international levels.

• WMO coordinates the activities of National Meteorological and Hydrological Services in 193 States and territories so that basic weather, climate and water services are made available to anyone who needs them.

• The Secretariat, headquartered in Geneva, is headed by the Secretary-General.

Manorama Yearbook app is now available on Google Play Store and iOS App Store