Western Australian temperature outlook
Issued 23 October 2013
The chances of the November to January maximum temperature exceeding the long-term median maximum temperature are greater than 60% over much of WA, except for the southwest. Odds increase to greater than 70% in the far north. So for every ten November to January 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.
The chances that the average minimum temperature for the November to January period will exceed the long-term median are greater than 60% over much of WA, except for the southwest. Probabilities rise to greater than 80% in the far north.
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 much of WA, except the west Pilbara and north Gascoyne which are only very weakly consistent.
The effect on minimum temperatures during this season is moderately consistent over much of WA, excluding parts of northwestern, central and eastern WA, which are only very weakly consistent.