The Ledger The Ledger
MILEPOST 1320
The ledger, through October 8
Mean absolute temperature error runs 2.25°F at day 1 and 4.19°F at day 7, over 511,658 settled forecast-observation pairs.
Every forecast this network publishes for a station with an ASOS report is compared against that report once the valid time has passed, and the residual is written down. This is the standing table for September 8–October 8, 2026.
| Lead | NDFD | NBM | pairs |
|---|---|---|---|
| Day 1 | 2.30 | 2.25 | 70,206 |
| Day 2 | 2.55 | 2.47 | 70,293 |
| Day 3 | 2.83 | 2.71 | 70,058 |
| Day 4 | 3.11 | 2.99 | 69,812 |
| Day 5 | 3.48 | 3.34 | 69,971 |
| Day 6 | 3.90 | 3.76 | 70,056 |
| Day 7 | 4.34 | 4.19 | 56,572 |
| Day 8 | — | 4.52 | 34,690 |
Mean absolute error, °F, temperature. ASOS reports at :53 and the forecast is stamped on the hour, so a forecast is paired with the nearest observation within 30 minutes and otherwise left unscored.
The numbers in this piece, with what they are measured against
| day-1 mean absolute temperature error, NBM Forecast Network verification ledger |
2.25 °F | of 34,724 September 8–October 8, 2026 |
| day-3 mean absolute temperature error, NBM Forecast Network verification ledger |
2.71 °F | of 34,574 September 8–October 8, 2026 |
| day-5 mean absolute temperature error, NBM Forecast Network verification ledger |
3.34 °F | of 34,487 September 8–October 8, 2026 |
| day-7 mean absolute temperature error, NBM Forecast Network verification ledger |
4.19 °F | of 34,506 September 8–October 8, 2026 |
| day-1 mean absolute temperature error, NDFD Forecast Network verification ledger |
2.3 °F | of 35,482 September 8–October 8, 2026 |
| day-3 mean absolute temperature error, NDFD Forecast Network verification ledger |
2.83 °F | of 35,484 September 8–October 8, 2026 |
| day-5 mean absolute temperature error, NDFD Forecast Network verification ledger |
3.48 °F | of 35,484 September 8–October 8, 2026 |
| day-7 mean absolute temperature error, NDFD Forecast Network verification ledger |
4.34 °F | of 22,066 September 8–October 8, 2026 |
- Milepost
- 1320 · laid 2026-10-08T00:25:13Z
- Desk
- ledger v1
- Method
- ASOS reports at :53 and the forecast is stamped on the hour, so a forecast is paired with the nearest observation within 30 minutes and otherwise left unscored.
- Source
- /home/maue/forecastpoints/data/verify/2026-09.ndjson
/home/maue/forecastpoints/data/verify/2026-10.ndjson - Digest
- a3d6d7f5141ac1792eb1c50d83cca54874f59c744730595c24f389540db7dc4b
- Machine
- JSON