The El Nino Southern Oscillation (ENSO) is an atmospheric ocean feedback pattern driven by the temperatures in the Pacific Ocean. ENSO has three different phases which include El Nino, Neutral and La Nina – depending on the phase, the impact on Australia’s climate differs. ENSO’s impact does not just stop at Australia but has a global reach on the climate too.
The Bureau of Meteorology (BoM) monitor the phases of ENSO as part of their forecast with an alert system ranging from Alert, Watch, Inactive, La Nina and El Nino. El Nino and La Nina essentially have opposing climate conditions. Currently, the BoM is predicting a “La Nina watch” warning as of the 21st of July outlook update, which is expected to persist. [1]
The outlook scenario for “La Nina watch” indicates that there is a possibility of a La Nina forming over the months ahead. Around the tropical Pacific, ocean temperatures are cooling which are indicative of La Nina conditions.
According to the BoM, the chance of La Nina forming around Spring has “increased to around 50%.” [1]
La Nina conditions for Australia will mean that daytime temperatures will decrease in southern Australia and total rainfall will increase in parts of eastern, northern, and central Australia. Generally, La Nina conditions last until the following Autumn, but there are cases of La Nina lasting for up to 3 years. [2]
