Retrospective report

Week of 24 August 2026

Week-Ahead Model - First Tier

Per-region forecast accuracy for the Week-Ahead Model - First Tier model group over the week of 24 August 2026.

Model revision 4

Generated 3 September 2026 at 5:09 pm (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	Price spike windows³
NSW1	40.11	-0.84	$80.19	$81.03	2
QLD1	23.40	-16.53	$49.93	$66.46	0
SA1	42.53	-7.28	$79.69	$86.97	0
TAS1	27.70	7.81	$78.07	$70.25	0
VIC1	28.47	-18.77	$58.69	$77.46	0

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	40.11	-0.84	$80.19	$81.03	2

Change in Forecasted Prices over the Price Spike in NSW1 between 2026-08-26 01:00:00 and 2026-08-26 13:30:00

Change in Forecasted Prices over the Prediction Interval in NSW1 using Week-Ahead Model - First Tier (Without Price Spikes)

QLD1

Region	MAE	Bias	Average predicted price	Average actual price	Price spike windows
QLD1	23.40	-16.53	$49.93	$66.46	0

SA1

Region	MAE	Bias	Average predicted price	Average actual price	Price spike windows
SA1	42.53	-7.28	$79.69	$86.97	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	27.70	7.81	$78.07	$70.25	0

VIC1

Region	MAE	Bias	Average predicted price	Average actual price	Price spike windows
VIC1	28.47	-18.77	$58.69	$77.46	0