National temperature outlook
Issued 27 November 2013
The chances of the summer maximum temperature exceeding the long-term median maximum temperature are greater than 60% over eastern Australia, the Top End of the NT, and isolated coastal regions (see map). Odds increase to greater than 70% over the Cape York Peninsula and southeast Queensland. 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 southwest WA. The chances of receiving a cooler or warmer than normal summer is roughly equal (i.e., close to 50%) over the remainder of the country.
The chances that the average minimum temperature for summer will exceed the long-term median are greater than 60% over Queensland, the northeastern half of NSW, the Top End of the NT, parts of the northwest coast of WA, and Tasmania. Odds increase to greater than 70% over southern Queensland, the Cape York Peninsula, and parts of the northwest coast.
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 broadscale climate affect Australian temperatures. During summer, historical accuracy shows the outlook for maximum temperatures to be moderately consistent over most of WA, the northern and southern parts of the NT, and eastern Australia. The central NT, western Queensland, eastern SA, western NSW and western Victoria are only weakly consistent, with southwest SA only very weakly consistent.
The effect on minimum temperatures during this season is moderately consistent over most of the country, excluding parts of central WA, the central NT, parts of western Queensland, western Victoria, and Tasmania which are only weakly consistent.