28 Day Rainfall Forecast
Perth Rain Forecast
Perth 28-day Rainfall Forecast
Sun Mon Tue Wed Thu Fri Sat17181920212223242526272829Low3031Feb 1Low23Low456Low7Low891011121314LowCHANCE OF RAINFALL WITHIN DISTRICTNil< 25%Low25 - 50%Medium50 - 75%High≥ 75%
Issue NotesIssued 17 Jan 2022
The hemispheric long wave pattern has remained stable in recent weeks. There are five main troughs. Currently the most significant troughs are near the longitudes of the southwest Indian Ocean, New Zealand, 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 1 February to 5 February, 6 February to 10 February, and 11 February to 15 February. Rain events originating in the tropics and moving south are possible about 16 January to 20 January, and 9 February to 13 February. Over Western Australia the strongest cold fronts should occur about 3 February to 7 February, and 12 February to 16 February.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.