The Bureau of Meteorology has issued an El Nino watch and says there’s about twice the normal likelihood that the climate influence associated with heatwaves and bushfires could form later this year.

Australia’s third-consecutive La Nina event has now ended with atmospheric and oceanic indicators in the Pacific having returned to neutral levels.

The El Nino Southern Oscillation (ENSO) monitored by climate models reflects swings between La Nina and El Nino conditions. An El Nino typically produces drier seasons and an increased risk of bushfire in Australia’s southeast, but the bureau says the influence of each event varies.

“International climate models suggest neutral ENSO conditions are likely to persist through the southern autumn,” the bureau says in its latest update today. “However, there are some signs that El Nino could form later in the year.”

The bureau says several models suggest an El Nino could develop, but accuracy when forecasting through autumn is lower than at other times of the year, and outlooks that extend past autumn should be viewed with some caution.

The Watch means there is a 50% chance of an El Nino this year, which is about twice the normal likelihood of an event forming in any year.

“An El Nino Watch is not a guarantee that El Nino will occur, rather it is an indication that some of the typical precursors of an event are currently observed,” it says.

The now-ended La Nina was declared in September, following two events associated with record flooding in Australia’s east.

The US-based National Oceanic and Atmospheric Administration (NOAA) has also declared the end of the La Nina, and says a forecaster consensus expects neutral conditions to remain through the coming months before a likely transition to El Nino later in the year.