you are not logged in | login or join us

Perth 28-day Rainfall Forecast

Sun
Mon
Tue
Wed
Thu
Fri
Sat
21
22
23
24
25
26
27
low
28
29
30
31
low
Jan 1
low
2
low
3
low
4
5
low
6
7
low
8
9
10
low
11
12
13
14
15
16
17
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 the southwest Indian Ocean, eastern Australia, the south Pacific, South America, and the Atlantic Ocean.
Summary:
Over southern and eastern Australia the cold front events with potential to bring widespread rain are now expected about 26 December to 30 December, 7 January to 11 January, and 17 January to 21 January. Rain events originating in the tropics and moving south are possible about 26 December to 30 December, 30 December to 3 January, and 5 January to 9 January.
Over Western Australia the strongest cold fronts should occur about 26 December to 30 December, 7 January to 11 January, and 17 January to 21 January.

Issued Dec 20

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.

Site search


Enter a postcode or town name for local weather, or text to search the site. » advanced search

Help with Weatherzone