Fairfax Media Network

Upper Derwent 28-day Rainfall Forecast

Sun
Mon
Tue
Wed
Thu
Fri
Sat
27
high
28
high
29
high
30
high
31
med
Aug 1
high
2
high
3
high
4
med
5
low
6
low
7
low
8
med
9
med
10
high
11
med
12
low
13
med
14
low
15
low
16
med
17
high
18
high
19
high
20
high
21
med
22
high
23
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 been relatively fast moving in recent weeks. There are six main troughs. Currently the most significant troughs are near the longitudes of the southwest Indian Ocean, Western Australia, New Zealand, 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 30 July to 3 August, 24 August to 28 August, and 28 August to 1 September. Rain events originating in the tropics and moving south are possible about 21 August to 25 August.
Over Western Australia the strongest cold fronts should occur about 30 July to 3 August, 7 August to 11 August, and 25 August to 29 August.

Issued Jul 26

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

NSW enjoying a warm and wet winter

12:27 EST

The first two months of winter have been particularly warm and wet, but that hasn't prevented extremely cold events.

Cunnamulla couple boosts spirits in outback Queensland town by refurbishing bakery

12:26 EST

Cunnamulla in far south-west Queensland has had its fair share of bad press in recent years.

Adelaide weather: Flood watch for Hills, Sealink ferries cancelled as cold front approaches SA

12:25 EST

A flood watch is current in the Mount Lofty Ranges near Adelaide as another cold front approaches the region.