Weather

Melbourne 28-day rainfall forecast

Sun Mon Tue Wed Thu Fri Sat
    21
Med
 
22
Med
 
23
Med
 
24
Med
 
25
Low
 
26
Med
 
27
 
 
28
Low
 
29
Low
 
30
Med
 
1
Low
Dec
2
Med
 
3
Low
 
4
Low
 
5
 
 
6
 
 
7
Low
 
8
Med
 
9
Med
 
10
Med
 
11
High
 
12
High
 
13
Med
 
14
High
 
15
High
 
16
Low
 
17
Med
 
18
Low
 
         

Chance of rainfall somewhere within district

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

Issue Notes

Issued 14 Nov 2017

The hemispheric long wave pattern has remained stable in recent weeks. There are five main troughs. Currently the most significant troughs are near the longitudes of South Africa, the southwest Indian Ocean, the Indian Ocean, New Zealand, and South America. Summary: Over southern and eastern Australia the cold front events with potential to bring widespread rain are now expected about 20 November to 24 November, 3 December to 7 December, and 17 December to 21 December. Rain events originating in the tropics and moving south are possible about 20 November to 24 November, 29 November to 3 December, and 7 December to 11 December. Over Western Australia the strongest cold fronts should occur about 20 November to 24 November, 3 December to 7 December, and 17 December to 21 December.

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.