|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 South Africa, Western Australia, New Zealand, 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 4 November to 8 November, 8 November to 12 November, and 12 November to 16 November. Rain events originating in the tropics and moving south are possible about 1 November to 5 November, 10 November to 14 November, and 21 November to 25 November.
Over Western Australia the strongest cold fronts should occur about 5 November to 9 November, 10 November to 14 November, and 14 November to 18 November.
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.
04:58 AEDT The New South Wales government is being urged to issue a natural disaster declaration for parts of the Wollondilly Shire, south-west of Sydney, after a storm trashed the region over the weekend.