Brisbane 28-day Rainfall Forecast
|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 four main troughs. Currently the most significant troughs are near the longitudes of South Africa, the Indian Ocean, Western Australia, New Zealand, and the southeast Pacific.
Over southern and eastern Australia the cold front events with potential to bring widespread rain are now expected about 6 October to 10 October, 17 October to 21 October, and 1 November to 5 November. Rain events originating in the tropics and moving south are possible about 12 October to 16 October, 23 October to 27 October, and 29 October to 2 November.
Over Western Australia the strongest cold fronts should occur about 6 October to 10 October, 11 October to 15 October, and 17 October to 21 October.
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.
The South Australian towns of Port Wakefield and Virginia are under threat from floodwaters as the Wakefield and Gawler rivers burst their banks.
A severe weather warning has been issued for much of southern Western Australia, with winds of more than 100 kilometres per hour raising fears about potential damage to homes and property.
Flood warnings are likely to stay in place across Tasmania for several days as rainfall continues, but the worst of the weather has passed, the weather bureau says.