The Bureau of Meteorology warns the likelihood of a La Nina weather event has increased to 70%, as the tropical Pacific approaches the temperature threshold.

However, climate models suggest any event is likely to be weak and short-lived, and not comparable to the strong 2010-12 La Nina.

As insuranceNEWS.com.au has previously reported, experts believe the developing system will not bring the usual increased rainfall to eastern Australia.

Sea surface temperature patterns in the Indian Ocean and closer to Australia are not typical of La Nina, reducing the likelihood of widespread summer rainfall.

La Nina can also increase the chance of prolonged warm spells for southeast Australia.