The Ledger The Ledger
MILEPOST 1161
The ledger, through September 21
Mean absolute temperature error runs 2.24°F at day 1 and 3.77°F at day 7, over 490,581 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 August 22–September 21, 2026.
| Lead | NDFD | NBM | pairs |
|---|---|---|---|
| Day 1 | 2.30 | 2.24 | 69,456 |
| Day 2 | 2.49 | 2.43 | 68,935 |
| Day 3 | 2.75 | 2.65 | 68,485 |
| Day 4 | 2.99 | 2.87 | 68,474 |
| Day 5 | 3.31 | 3.17 | 67,513 |
| Day 6 | 3.60 | 3.48 | 65,854 |
| Day 7 | 3.92 | 3.77 | 51,504 |
| Day 8 | — | 4.06 | 30,360 |
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 |
2.24 °F | of 35,028 August 22–September 21, 2026 |
| day-3 mean absolute temperature error, NBM Forecast Network verification ledger |
2.65 °F | of 34,956 August 22–September 21, 2026 |
| day-5 mean absolute temperature error, NBM Forecast Network verification ledger |
3.17 °F | of 33,988 August 22–September 21, 2026 |
| day-7 mean absolute temperature error, NBM Forecast Network verification ledger |
3.77 °F | of 31,500 August 22–September 21, 2026 |
| day-1 mean absolute temperature error, NDFD Forecast Network verification ledger |
2.3 °F | of 34,428 August 22–September 21, 2026 |
| day-3 mean absolute temperature error, NDFD Forecast Network verification ledger |
2.75 °F | of 33,529 August 22–September 21, 2026 |
| day-5 mean absolute temperature error, NDFD Forecast Network verification ledger |
3.31 °F | of 33,525 August 22–September 21, 2026 |
| day-7 mean absolute temperature error, NDFD Forecast Network verification ledger |
3.92 °F | of 20,004 August 22–September 21, 2026 |
- Milepost
- 1161 · laid 2026-09-21T00:26:34Z
- 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/2026-08.ndjson
/home/maue/forecastpoints/data/verify/2026-09.ndjson - Digest
- 63d2db2f8319199ebd04970890f726c4797bde3ab77fd39c1a735b55ea4acfd0
- Machine
- JSON