Fairfax Media Network

Lower Derwent 28-day Rainfall Forecast

Sun
Mon
Tue
Wed
Thu
Fri
Sat
17
low
18
19
low
20
high
21
high
22
high
23
med
24
high
25
high
26
low
27
med
28
low
29
30
Dec 1
low
2
med
3
high
4
med
5
med
6
med
7
med
8
low
9
low
10
low
11
med
12
low
13
low
14
med
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 remained stable 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, eastern Australia, the south 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 23 November to 27 November, 1 December to 5 December, and 9 December to 13 December. Rain events originating in the tropics and moving south are possible about 24 November to 28 November, 4 December to 8 December, and 9 December to 13 December.
Over Western Australia the strongest cold fronts should occur about 22 November to 26 November, 2 December to 6 December, and 6 December to 10 December.

Issued Nov 16

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.

Display Your Local Weather

Weather News

Perth's summer set to be a hot one according to the Bureau of Meteorology summer forecast

07:27 EDT

A spring scorcher today of 37 degrees Celsius is shaping up as a taste of things to come, with a hot summer heading our way — in stark contrast to the unusually cool summer of 2017-18.

New weather app 'a quantum leap' for understanding extreme events

06:45 EDT

Rain of biblical proportions, heatwaves, tornadoes and bushfires — extreme weather events happen around the world on a regular basis and Australian scientists are hoping to improve their forecasting with the help of citizen scientists.

Expansion of telehealth services for drought-affected farmers marks a good step forward, doctor says

06:45 EDT

As Australian telehealth services expand to accommodate drought-affected farmers, experts say there is still room for substantial growth in the sector.