Weather

Southwest 28-day rainfall forecast

Sun Mon Tue Wed Thu Fri Sat
    25
 
 
26
 
 
27
 
 
28
 
 
29
 
 
30
 
 
1
 
May
2
Med
 
3
Low
 
4
 
 
5
 
 
6
 
 
7
Low
 
8
 
 
9
 
 
10
 
 
11
 
 
12
Low
 
13
 
 
14
 
 
15
 
 
16
 
 
17
 
 
18
 
 
19
 
 
20
 
 
21
 
 
22
 
 
         

Chance of rainfall somewhere within district

Nil
<25%
Low
25-50%
Medium
50-75%
High
≥75%

Issue Notes

Issued 24 Apr 2017

The hemispheric long wave pattern has remained stable in recent weeks. There are four main troughs. Currently the most significant troughs are near the longitudes of the Indian Ocean, eastern Australia, the southeast Pacific, and the Atlantic Ocean. Summary: Over southern and eastern Australia the cold front events with potential to bring widespread rain are now expected about 1 May to 5 May, 5 May to 9 May, and 10 May to 14 May. Rain events originating in the tropics and moving south are possible about 22 April to 26 April. Over Western Australia the strongest cold fronts should occur about 29 April to 3 May, 4 May to 8 May, and 10 May to 14 May.

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.