The pattern of seasonal maximum temperature odds across Australia is a result of
the combined effects from above average temperatures in the central to southeast
Indian Ocean, and the cooler than average temperatures in the equatorial Pacific
Averaged over March to May, the chances are between 30 to 40% for above-normal maximum
temperatures over the southern half of Queensland and the northeast half of NSW (see map).
This means that below-normal maximum temperatures have a 60 to 70% chance of occurring.
So for every ten years with ocean patterns like the current, about six or seven
autumns are expected to be cooler than average over these parts of the country, with about
three or four being warmer.
Outlook confidence is related to how consistently the Pacific and Indian
Oceans affect Australian temperatures. During autumn, history shows this effect on maximum temperatures
to be moderately consistent over Victoria, Tasmania, the far north and south of WA,
and much of Queensland and the NT. Elsewhere the effect is weak (see background information).
So this outlook should be used with caution over inland NSW and far southwest
In contrast, minimum temperatures averaged over autumn are favoured to be warmer than normal across
most of Queensland, NSW and the southern half of WA (see map). The chances of increased
overnight warmth (averaged over the coming three months) are mainly between 60
and 75% in these areas. Across the rest of the country, the chances of the
seasonal mean minimum being above the long-term average are typically between 45 and 60%,
except in an area in the western NT into northern WA where the chances approach 40%.
History shows the oceans' effect on minimum temperatures during autumn
to be moderately consistent over large parts of the country.