28 Day Rainfall Forecast
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Southwest Rain Forecast
Southwest 28-day Rainfall ForecastSun Mon Tue Wed Thu Fri Sat 171819Low20212223242526Low27Low28Med29Low30LowMay 1Low2Low34Med567Low8Low9Med10Med11Med12Med13Med14Med15LowCHANCE OF RAINFALL WITHIN DISTRICTNil< 25%Low25 - 50%Medium50 - 75%High≥ 75%Issue Notes
Issued 17 Apr 2021The hemispheric long wave pattern has been relatively slow moving in recent weeks. There are four main troughs. Currently the most significant troughs are near the longitudes of South Africa, the Indian Ocean, Western Australia, eastern Australia, and the southeast Pacific.
Summary:
Over southern and eastern Australia the cold front events with potential to bring widespread rain are now expected about 2 May to 6 May, 15 May to 19 May, and 19 May to 23 May. Rain events originating in the tropics and moving south are possible about 15 April to 19 April. Over Western Australia the strongest cold fronts should occur about 27 April to 1 May, 2 May to 6 May, and 10 May to 14 May.
Forecast ExplanationThis 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.
