Western Australian temperature outlook

Issued 24 July 2014

Warmer nights for most parts of WA, warmer days in the southwest

Text details of chance of warmer maximum and minimum temperatures

Summary

  • Warmer nights are more likely for most of WA
  • Warmer days are more likely for parts of the southwest
  • Climate influences include a brief Indian Ocean Dipole, and near-average Pacific waters
  • Outlook accuracy for maximum temperatures is moderate over much of the south and west, and coastal parts of the Kimberley district
  • Outlook accuracy for minimum temperatures is moderate or better over the Kimberley district but is generally low elsewhere
  • 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 of warmer than normal maximum temperatures for August to October are close to 50% for most of WA. The odds of a warmer than normal season are greater than 60% in the southwest (rising to greater than 80% in parts of the South West, Great Southern and South Coastal districts), along the southern coast, and eastern parts of the Kimberley district.

The chances of warmer than normal minimum temperatures for August to October are greater than 60% for most parts of WA, strengthening to greater than 80% in the southwest. The chances of warmer than normal average minimum temperatures in western parts of the Gascoyne and Pilbara districts are close to 50%.

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 over much of the south and west, and coastal parts of the Kimberley district
  • Low to very low over the rest of WA

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

  • Moderate to high over the Kimberley district
  • Low to very low for the rest of WA (see map)