The Bureau of Meteorology says the chance of an El Nino developing this year has risen to 70%, triple the normal likelihood.

The bureau issued an El Nino alert last week after maintaining a “watch” status since late January.

“Tropical Pacific sea surface temperatures have touched on El Nino thresholds for the past three weeks, while waters below the surface are also slightly warmer than average,” it says.

Most international climate models suggest sea surface temperatures in the central tropical Pacific Ocean are likely to remain at El Nino levels this winter.

El Nino typically brings drier than average conditions for eastern Australia during winter and spring, and warmer days across southern Australia. Impacts can include fewer tropical cyclones.

During autumn an El Nino’s influence tends to be weaker, but it can bring drier conditions to southern Australia.