Southeast Australian temperature outlook

Issued 24 July 2014

A warmer season likely for most of southeast Australia

Text details of chance of warmer maximum and minimum temperatures

Summary

  • Warmer days are more likely for most of southeast Australia, excluding the northern half of SA and northwest NSW
  • Warmer nights are more likely most of southeast Australia, with stongest odds across southern Victoria, southeast NSW and Tasmania
  • Climate influences include a brief negative Indian Ocean Dipole, and near-average Pacific waters
  • Outlook accuracy for maximum temperatures is moderate to high over most of NSW, Victoria, Tasmania and central and eastern districts of SA, but low for western and northern SA
  • Minimum temperature accuracy is low to very low throughout most of NSW, Victoria and northern SA. See accuracy tab for map.
  • Details are summarised in our new monthly Climate and Water Outlook video
Probability of exceeding median maximum temperature, larger view Probability of exceeding median minimum temperature, larger view

Details

The chances that the August to October maximum temperature outlook will exceed the median maximum temperature are greater than 60% over most of NSW, Victoria, Tasmania, southeast SA. Chances are greater than 80% over southern Victoria and Tasmania. So for every ten August to October outlooks with similar odds to these, about six to eight of them would be warmer than average over these areas, while about two to four would be cooler.

Across the northern half of SA and the far northwest of NSW the chances of a warmer or cooler August to October are roughly equal.

The chances that the average minimum temperature for August to October 2014 will exceed the long-term median are greater than 60% over southeast Australia. Chances rise to greater than 80% over southern Victoria, Tasmania, and southeast NSW (see map).

Climate influences

Warming of the tropical Pacific Ocean over the past several months has primed the climate system for an El Niño in 2014. However, in the absence of the necessary atmospheric response, Pacific Ocean temperatures have either stabilised or some cooling has occurred. Despite some easing in the model outlooks, a majority of international climate models still indicate El Niño is likely to develop during spring 2014.

The Indian Ocean Dipole (IOD) index has been below −0.4°C (the negative IOD threshold) since mid-June. Model outlooks suggest the IOD is likely to return to neutral by spring. A negative IOD typically brings wetter winter and spring conditions to inland and southern Australia. It is possible that the effects of the Indian Ocean and Pacific are competing to some degree, and hence are cancelling each other out.

How accurate is the outlook?

Maximum temperature outlook accuracy for the August to October period is:

  • Moderate to high over most of NSW, Victoria, Tasmania and central and eastern districts of SA
  • Low to very low over western and northern parts of SA
Minimum temperature outlook accuracy for the August to October period is:
  • Moderate over western and northeast parts of South Australia and Tasmania
  • Low to very low throughout most of NSW, Victoria, and northern and southeast SA