Retrospective report

Week of 31 August 2026

Week-Ahead Model - First Tier

Per-region forecast accuracy for the Week-Ahead Model - First Tier model group over the week of 31 August 2026.

Model revision 4

Generated 7 September 2026 at 7:43 am (Sydney time)

*Note that this model revision was published more recently than the first time a price in this retrospective period was forecast. As a result, this report evaluates the model's performance for a subset of forecasts in the retrospective period.

Region	MAE¹	Bias²	Average predicted price	Average actual price
NSW1	23.88	3.29	$56.99	$53.71
QLD1	15.51	0.70	$46.58	$45.88
SA1	36.08	-3.49	$37.19	$40.69
TAS1	35.21	23.08	$59.06	$35.98
VIC1	25.20	-6.29	$26.76	$33.05

¹Mean Absolute Error (MAE) is the average absolute difference between forecast and actual prices.

²Bias is the average difference between forecast and actual prices.

³To maintain an informative scale, we charted price spikes separately to other prices. We plotted the 6 hours before and after the RRP exceeded $500 as separate, region-specific charts. These price spikes are capped at $500 in the full region prediction charts.

NSW1

Region	MAE	Bias	Average predicted price	Average actual price	Price spike windows
NSW1	23.88	3.29	$56.99	$53.71	0

QLD1

Region	MAE	Bias	Average predicted price	Average actual price	Price spike windows
QLD1	15.51	0.70	$46.58	$45.88	0

SA1

Region	MAE	Bias	Average predicted price	Average actual price	Price spike windows
SA1	36.08	-3.49	$37.19	$40.69	0

Change in Forecasted Prices over the Prediction Interval in SA1 using Week-Ahead Model - First Tier

TAS1

Region	MAE	Bias	Average predicted price	Average actual price	Price spike windows
TAS1	35.21	23.08	$59.06	$35.98	0

VIC1

Region	MAE	Bias	Average predicted price	Average actual price	Price spike windows
VIC1	25.20	-6.29	$26.76	$33.05	0