28 Day Rainfall Forecast
Sydney Rain Forecast
Sydney 28-day Rainfall Forecast
Sun Mon Tue Wed Thu Fri Sat10Low11Low12Low1314Low15Low161718Low192021Low222324Low25Low26Med27Low28Med29Low3031HigJan 1Low2Med3Med4Med5Hig6Med7HigCHANCE OF RAINFALL WITHIN DISTRICTNil< 25%Low25 - 50%Medium50 - 75%High≥ 75%
Issue NotesIssued 9 Dec 2021
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, Western Australia, New Zealand, the south Pacific, and the Atlantic Ocean.
Over southern and eastern Australia the cold front events with potential to bring widespread rain are now expected about 17 December to 21 December, 21 December to 25 December, and 10 January to 14 January. Rain events originating in the tropics and moving south are possible about 27 December to 31 December, and 4 January to 8 January. Over Western Australia the strongest cold fronts should occur about 18 December to 22 December, 3 January to 7 January, and 10 January to 14 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.