28 Day Rainfall Forecast
Sydney Rain Forecast
Sydney 28-day Rainfall Forecast
Sun Mon Tue Wed Thu Fri Sat5Hig67891011Low12131415Low16Low17Med18Hig19Hig20Med21Med2223Low24Low25Low26Med27Low28Med29Med30Med31Jan 12LowCHANCE OF RAINFALL WITHIN DISTRICTNil< 25%Low25 - 50%Medium50 - 75%High≥ 75%
Issue NotesIssued 4 Dec 2020
The hemispheric long wave pattern has remained stable in recent weeks. There are six main troughs. Currently the most significant troughs are near the longitudes of South Africa, the Indian Ocean, eastern Australia, the south Pacific, the southeast Pacific, South America, and the Atlantic Ocean.
Over southern and eastern Australia the cold front events with potential to bring widespread rain are now expected about 22 December to 26 December, 26 December to 30 December, and 6 January to 10 January. Rain events originating in the tropics and moving south are possible about 20 December to 24 December, 27 December to 31 December, and 3 January to 7 January. Over Western Australia the strongest cold fronts should occur about 16 December to 20 December, 23 December to 27 December, and 7 January to 11 January.Forecast Explanation
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.