Weather

Southwest 28-day rainfall forecast

Sun Mon Tue Wed Thu Fri Sat
          30
High
 
1
High
Jul
2
Low
 
3
Low
 
4
Low
 
5
Low
 
6
 
 
7
Low
 
8
High
 
9
Med
 
10
Med
 
11
Med
 
12
Med
 
13
Low
 
14
Med
 
15
Low
 
16
Low
 
17
 
 
18
Med
 
19
Med
 
20
Low
 
21
 
 
22
 
 
23
 
 
24
Low
 
25
Low
 
26
Med
 
27
High
 
   

Chance of rainfall somewhere within district

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

Issue Notes

Issued 28 Jun 2017

The hemispheric long wave pattern has been relatively fast moving in recent weeks. There are seven main troughs. Currently the most significant troughs are near the longitudes of South Africa, the Indian Ocean, eastern Australia, New Zealand, 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 12 July to 16 July, 25 July to 29 July, and 31 July to 4 August. Rain events originating in the tropics and moving south are possible about 26 June to 30 June. Over Western Australia the strongest cold fronts should occur about 9 July to 13 July, 25 July to 29 July, and 1 August to 5 August.

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.