Australia confirms rare ‘triple dip’ La Nina; rain, flood expected in some parts of world
The Australian Bureau of Meteorology has confirmed the development of La Nina weather pattern for the third consecutive year in the Pacific, upping the risk of rain and floods in different parts of the world.
According to the World Meteorological Organization, a UN agency, it is for the first time in this century that La Niña has returned for three consecutive years.
"It is exceptional to have three consecutive years with a La Nina event," WMO Secretary-General Petteri Taalas said in a statement.
La Niña weather pattern is one of the three phases of the El Niño Southern Oscillation (ENSO).
It refers to the unusual cooling of the tropical eastern Pacific. La Nina, which means The Little Girl in Spanish, represent periods of below-average sea surface temperatures across the east-central Equatorial Pacific.
Under this weather pattern, the atmospheric circulation across the tropical Pacific is set up so that warm waters to Australia's north-east and strong trade winds pump moisture into the atmosphere along Australia's east coast.
When the right systems come along, they then tap into that moisture, bringing about heavy rains and flooding.
The bureau, in its fortnightly update of Australia’s climate drivers, said that key atmospheric and oceanic indicators of the El Niño–Southern Oscillation (Enso) showed “an established La Niña”.
“Tropical Pacific sea surface temperatures have been cooling since June and are now at La Niña thresholds,” the bureau said.
“Models indicate this La Niña event may peak during the spring and return to neutral conditions early in 2023,” it added.
Impacts of La Nina across the globe
La Nina tends to bring milder winters in Northern Europe, especially UK, and colder winters in southern and western Europe, leading to snow in the Mediterranean region. It reduces the number of autumnal hurricanes across Europe.
It is in the American continent where the extreme climate conditions due to La Nina are felt the most.
In the Pacific, stronger winds arrive along the equatorial region. While it leads to favourable conditions for hurricanes in the Caribbean and central Atlantic area. In various states of US, frequent tornados are observed.
In Australia, Indonesia and other parts of Asia, La Nina brings heavy rainfall and can even cause more lightning activity in the Gulf of Mexico and along the Gulf Coast and increase the number of hurricanes and tropical cyclones, according to the National Oceanic and Atmospheric Administration.
The condition is reversed in South America, where La Nina causes drought, especially in countries of Peru and Ecuador.
The situation is the same in East Africa as well. The fourth season of failed rains is currently causing one of the worst droughts East Africa has seen in decades.
According to the UN’s World Food Programme, Ethiopia, Kenya and Somalia are on the brink of an unprecedented humanitarian catastrophe, and up to 20 million people are at risk of severe hunger.
