Western Australian temperature outlook

Issued 27 November 2013

Warmer summer likely for northwest coast of Western Australia

Text details of chance of warmer maximum and minimum temperatures

Summary

  • Warmer days and nights are likely in the coastal areas of far north, northwest and southeast of WA
  • Cooler days and nights are likely in parts of southwest WA
  • Climate influences include a neutral tropical Pacific, and local sea surface temperature patterns
  • Outlook accuracy for maximum and minimum temperatures is moderate over most of WA.
Probability of exceeding median maximum temperature, larger view Probability of exceeding median minimum temperature, larger view

Details

The chances of the summer maximum temperature exceeding the long-term median are greater than 60% over coastal areas of the far north, northwest and southeast of WA (see map). So for every ten summer outlooks with similar odds to these, about six or seven of them would be expected to be warmer than average over these areas, while about three or four years would be cooler.

Conversely, the chances of exceeding the median maximum temperature is less than 40% over parts of southwest WA. The chances of receiving a cooler or warmer than normal summer over the remainder of the State are close to 50%, or roughly equal.

The chances that the average minimum temperature for summer will exceed the long-term median are greater than 60% over areas of the far north, northwest and southeast coast of WA, whilst parts of southwest WA show a 40% chance of exceeding the long-term median.

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. This means there is no strong shift in the odds from the tropical Pacific in this outlook.

With major climate influences likely to remain neutral (and hence have lesser impact upon Australia) over the coming months, secondary influences, such as the pattern of warmer-than-normal sea surface temperatures around the Australian continent are tending to drive the Australian climate.

How accurate is the outlook?

Outlook accuracy is related to how consistently the oceans and broad scale climate affect Australian temperatures. During summer, historical accuracy shows the outlook for maximum temperatures to be moderately consistent over most of WA.

The effect on minimum temperatures during this season is also moderately consistent over most of WA.