Retrospective report

Week of 5 October 2026

Week-Ahead Model - First Tier

Per-region forecast accuracy for the Week-Ahead Model - First Tier model group over the week of 5 October 2026.

Model revision 4

Generated 12 October 2026 at 8:48 am (Sydney time)

Region	MAE¹	Bias²	Average predicted price	Average actual price	Price spike windows³
NSW1	87.50	-68.21	$67.42	$135.62	4
QLD1	50.24	-46.44	$56.98	$103.42	1
SA1	85.47	41.39	$75.84	$34.45	2
TAS1	56.53	31.60	$70.30	$38.70	0
VIC1	39.58	-13.86	$22.38	$36.23	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	87.50	-68.21	$67.42	$135.62	4

Change in Forecasted Prices over the Price Spike in NSW1 between 2026-10-08 23:30:00 and 2026-10-09 11:30:00

Change in Forecasted Prices over the Price Spike in NSW1 between 2026-10-10 01:30:00 and 2026-10-10 13:30:00

Change in Forecasted Prices over the Price Spike in NSW1 between 2026-10-11 10:30:00 and 2026-10-11 22:30:00

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	50.24	-46.44	$56.98	$103.42	1

Change in Forecasted Prices over the Prediction Interval in QLD1 using Week-Ahead Model - First Tier (Without Price Spikes)

SA1

Region	MAE	Bias	Average predicted price	Average actual price	Price spike windows
SA1	85.47	41.39	$75.84	$34.45	2

Change in Forecasted Prices over the Price Spike in SA1 between 2026-10-09 01:30:00 and 2026-10-09 13:30:00

Change in Forecasted Prices over the Price Spike in SA1 between 2026-10-11 17:30:00 and 2026-10-12 05:30:00

Change in Forecasted Prices over the Prediction Interval in SA1 using Week-Ahead Model - First Tier (Without Price Spikes)

TAS1

Region	MAE	Bias	Average predicted price	Average actual price	Price spike windows
TAS1	56.53	31.60	$70.30	$38.70	0

VIC1

Region	MAE	Bias	Average predicted price	Average actual price	Price spike windows
VIC1	39.58	-13.86	$22.38	$36.23	0