Roper-McArthur 28-day Rainfall Forecast
|Chance of rainfall within district|
25% to 50%
50% to 75%
The hemispheric long wave pattern has remained stable in recent weeks. There are five main troughs. Currently the most significant troughs are near the longitudes of the southwest Indian Ocean, New Zealand, the south Pacific, and the Atlantic Ocean.
Over southern and eastern Australia the cold front events with potential to bring widespread rain are now expected about 8 September to 12 September, 21 September to 25 September, and 26 September to 30 September. Rain events originating in the tropics and moving south are possible about 18 September to 22 September.
Over Western Australia the strongest cold fronts should occur about 5 September to 9 September, 16 September to 20 September, and 26 September to 30 September.
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.
A band of rain sweeping over all districts in Victoria tomorrow may cause flooding in the state‚??s northeast.
The final rainband of the season is sweeping across South Australia today, but the heaviest rain is going to fall where it shouldn't.
Farmer confidence in Tasmania has dropped to a three-year low off the back of major flooding in the state's north and retrospective cuts to milk prices.