The Bureau of Meteorology has simultaneously declared the end of La Niña and an El Niño Watch, indicating a potential rapid shift to hot, dry weather in 2023.
La Niña's demise was expected as ocean temperatures across the Pacific have been returning to normal for months and was already declared finished last week by the National Oceanic and Atmospheric Administration (NOAA).
However, eastern Pacific temperatures are warming so quickly that, at the current rate, the western part of the ocean will be within El Niño territory within months, prompting the BOM's quick status shift to "El Niño watch".
A watch declaration is not an announcement that the phase has arrived, rather an indication there is a 50 per cent chance of of it developing during the coming winter or spring.
El Niño is the name used to describe the warm phase of the Pacific when sea surface temperatures rise along the equator, but it is not a synonym for hot and dry weather in Australia.
The last El Niño was in 2015, and the recent drought and bushfires, occurred mostly in a neutral phase in the Pacific.
During El Niño, there is a shift in convection and cloud away from the western Pacific to the central and eastern Pacific, leading to a reduction in rain and increase in temperatures across northern and eastern Australia.
While El Niño has an infamous reputation for bringing drought, the impacts are mostly confined to winter and spring and, therefore, for Australia, are less severe than a La Niña event, which can affect the weather for nearly 12 months.
Although El Niños have historically been responsible for dry years, all events are different and there is no guarantee rain will be below average in any one location.
The 2015 event brought severe drought to Tasmania, Victoria, tropical Queensland and southern South Australia, but left NSW and the Northern Territory unscathed.
