Southeast Australian temperature outlook

Issued 23 October 2013

A warm season likely for most of southeast Australia

Text details of chance of warmer maximum and minimum temperatures

Summary

  • Warmer days and nights are more likely over most of southeast Australia
  • Climate influences include warmer than average sea surface temperatures around Australia, and a neutral tropical Pacific
  • Outlook accuracy for maximum and minimum temperatures is moderate over most of southeast Australia
Probability of exceeding median maximum temperature, larger view Probability of exceeding median minimum temperature, larger view

Details

The chances of the November to January maximum temperature exceeding the long-term median maximum temperature are greater than 60% across southeast Australia. Odds increase to greater than 70% throughout northern parts of NSW and northeast SA. So for every ten November to January outlooks with similar odds to these, about six to eight of them would be expected to be warmer than average over these areas, while about two to four years would be cooler.

The chances that the average minimum temperature for the November to January period will exceed the long-term median are greater than 60% over most of southeast Australia, except for the lower southeast of SA and southwest Victoria. Probabilities rise to greater than 70% over northeast SA, and most of NSW.

Climate influences

The tropical Pacific has remained ENSO-neutral since mid-2012. The dynamical seasonal outlook model suggests ENSO-neutral conditions will remain for the rest of 2013.

The Indian Ocean Dipole (IOD) is neutral, and is expected to remain so for the next month. Beyond that time, the effect of the IOD on Australian climate from December through to April is limited, and is therefore not an influence on the outlooks during this period.

With the main climate influences likely to remain neutral (and hence have lesser impact upon Australia) over the coming months, secondary influences, such as warmer-than-normal oceans around the continent are tending to drive the Australian climate patterns.

How accurate is the outlook?

Outlook accuracy is related to how consistently the oceans and broadscale climate affect Australian temperatures. During the November to January period, historical accuracy shows the outlook for maximum temperatures to be moderately consistent over most Australia, except for Tasmania which is weakly consistent.

The effect on minimum temperatures during this season is moderately consistent over most of the southeast Australia, excluding the lower southeast of SA and the north coast of NSW, which are only weakly to very weakly consistent.