|Chance of rainfall within district|
25% to 50%
50% to 75%
The hemispheric long wave pattern has been relatively slow moving in recent weeks. There are four main troughs. Currently the most significant troughs are near the longitudes of the southwest Indian Ocean, eastern Australia, the southeast Pacific, and the Atlantic Ocean.
Over southern and eastern Australia the cold front events with potential to bring widespread rain are now expected about 10 August to 14 August, 18 August to 22 August, and 30 August to 3 September. Rain events originating in the tropics and moving south are possible about 21 August to 25 August, and 25 August to 29 August.
Over Western Australia the strongest cold fronts should occur about 1 August to 5 August, 6 August to 10 August, and 10 August to 14 August.
This forecast is produced by a multi-model ensemble consisting of dynamical atmospheric models, which are forced by the latest observed atmosphere, ocean, land and ice conditions. The models are designed to simulate features of the real atmosphere, including the daily movement of long and short wave patterns in the Southern Hemisphere.
The future probability of rain in each district is estimated using output from the multi-model ensemble, combined with historical information about the difference between the model forecasts and observed rainfall.
In this deterministic framework the skill of the forecast tends to decrease with time, however the forecasts are updated daily to provide the latest estimates of rainfall probability out to 28 days.
08:03 AEST Tropical storm Nepartak is sitting off the east of Japan's largest island and is forecast to skirt along its east coast tonight before making landfall well north of Tokyo some time tomorrow.