Northwest 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 five main troughs. Currently the most significant troughs are near the longitudes of the southwest Indian Ocean, Western Australia, the south Pacific, 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 1 October to 5 October, 6 October to 10 October, and 17 October to 21 October. Rain events originating in the tropics and moving south are possible about 1 October to 5 October, and 7 October to 11 October.
Over Western Australia the strongest cold fronts should occur about 1 October to 5 October, 6 October to 10 October, and 14 October to 18 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.
Wet weather "on par" with a system that caused widespread flooding across Adelaide earlier this month has been forecast to hit the Mount Lofty Ranges on Wednesday and Thursday.
New South Wales Premier Mike Baird has toured the flood-hit town of Forbes, in the state's central west, where he has thanked State Emergency Service (SES) volunteers for their efforts.
Agriculture authorities are monitoring the fallout from Canberra's recent above-average rainfall, but say the capital region has seen the worst of the downpours.