Click to watch four minute video presentation of the rainfall and temperature forecast for autumn 2018.
May-July 2018 rainfall outlook:
Drier three months likely in southwest Australia
Southwest Australia and parts of western Victoria have an increased chance of a drier than average May to July.
In contrast, a wetter than average season is likely for far eastern Victoria and eastern Tasmania. Parts of northern Australia are also likely to be wetter, however, rainfall during the start of the northern Australian dry season (May-September) is typically low, meaning little rainfall is needed to exceed the median. Elsewhere, the chances of a wetter or drier season are roughly equal.
Historical outlook accuracy for May to July rainfall is moderate over western and southern WA, the southern NT, southeast SA and the eastern States. See map for more detail.
May 2018 rainfall outlook:
June 2018 rainfall outlook:
Chances of a warmer May increase nation-wide
May days and nights are very likely to be warmer for much of the country. For daytime temperatures, chances are highest (greater than 80%) across northern and eastern parts of the country.
May to July daytime temperatures are likely to be warmer than average for southern Australia, including southwest WA, southeast NSW, Victoria and Tasmania. Chances are highest (greater than 80%) in Tasmania.
Night-time temperatures are likely to be warmer than average for southern Australia (except the southwest) while eastern Queensland is likely to have cooler than average nights.
Historical accuracy for maximum temperatures is moderate to high over most of Australia for May to July. Minimum temperature accuracy is also moderate to high for most of Australia, except parts of southeast mainland Australia where accuracy is moderate to low.
Minimum temperature outlook:
Maximum temperature outlook:
Source: Bureau of Meteorology
Comparison – previous forecast versus actual rainfall
Maps below compare BOM’s rainfall forecast for December 2017 to February 2018, issued in 30 November 2017, with actual rainfall deciles recorded over the December 2017 to February 2018 period.
FORECAST MEDIAN RAINFALL JAN-MARCH 2018:
RAINFALL DECILES RECORDED JAN-MARCH 2018:
Scroll between images below: