| Chance of rainfall within district | |||
|---|---|---|---|
| nil < 25% |
low 25% to 50% |
med 50% to 75% |
high ≥ 75% |
The hemispheric long wave pattern has been relatively slow moving in recent weeks. There are three main troughs. Currently the most significant troughs are near the longitudes of the southwest Indian Ocean, Western Australia, and the southeast Pacific.
Summary:
Over southern and eastern Australia the cold front events with potential to bring widespread rain are now expected about 2 April to 6 April, 14 April to 18 April, and 21 April to 25 April. Rain events originating in the tropics and moving south are possible about 1 April to 5 April, 12 April to 16 April, and 21 April to 25 April.
Over Western Australia the strongest cold fronts should occur about 1 April to 5 April, 13 April to 17 April, and 17 April to 21 April.
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.