|Chance of rainfall within district|
25% to 50%
50% to 75%
The hemispheric long wave pattern has been relatively fast moving in recent weeks. There are six main troughs. Currently the most significant troughs are near the longitudes of South Africa, the southwest Indian Ocean, the Indian Ocean, Western Australia, New Zealand, South America, and the Atlantic Ocean.
Over southern and eastern Australia the cold front events with potential to bring widespread rain are now expected about 30 April to 4 May, 4 May to 8 May, and 18 May to 22 May. Rain events originating in the tropics and moving south are possible about 19 May to 23 May, and 26 May to 30 May.
Over Western Australia the strongest cold fronts should occur about 30 April to 4 May, 4 May to 8 May, and 28 May to 1 June.
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.
09:09 EST As communities in NSW begin the huge clean up after devastating wild weather this week, residents in the south-west Queensland town of Charleville have held a lantern parade to mark the 25th anniversary of their worst flood event.