Weather

Southwest 28-day rainfall forecast

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

Chance of rainfall somewhere within district

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

Issue Notes

Issued 24 Jun 2018

The hemispheric long wave pattern has been relatively slow moving in recent weeks. There are six main troughs. Currently the most significant troughs are near the longitudes of South Africa, the southwest Indian Ocean, Western Australia, the south Pacific, 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 29 June to 3 July, 9 July to 13 July, and 20 July to 24 July. Rain events originating in the tropics and moving south are possible about 6 July to 10 July. Over Western Australia the strongest cold fronts should occur about 9 July to 13 July, 17 July to 21 July, and 26 July to 30 July.

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.