ACT 28-day Rainfall Forecast

Sun

Mon

Tue

Wed

Thu

Fri

Sat

Jan 1

Chance of rainfall within district
nil < 25%	low 25% to 50%	med 50% to 75%	high ≥ 75%

Issue Notes

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, eastern Australia, the south Pacific, and the southeast Pacific.
Summary:
Over southern and eastern Australia the cold front events with potential to bring widespread rain are now expected about 2023-12-09, 2023-12-14 and 2024-01-05. Rain events originating in the tropics and moving south are possible about 2023-12-28, 2024-01-01 and 2024-01-05. Over Western Australia the strongest cold fronts should occur about 2023-12-08, 2023-12-14 and 2023-12-22.

Issued Dec 9

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.