The Ledger The Ledger
MILEPOST 1147
The ledger, through September 20
Mean absolute temperature error runs 2.23°F at day 1 and 3.72°F at day 7, over 481,268 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 21–September 20, 2026.
| Lead | NDFD | NBM | pairs |
|---|---|---|---|
| Day 1 | 2.29 | 2.23 | 68,847 |
| Day 2 | 2.48 | 2.42 | 68,550 |
| Day 3 | 2.74 | 2.64 | 68,401 |
| Day 4 | 2.97 | 2.87 | 67,488 |
| Day 5 | 3.27 | 3.15 | 65,849 |
| Day 6 | 3.57 | 3.46 | 63,438 |
| Day 7 | 3.85 | 3.72 | 49,543 |
| Day 8 | — | 4.00 | 29,152 |
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 |
2.23 °F | of 34,949 August 21–September 20, 2026 |
| day-3 mean absolute temperature error, NBM Forecast Network verification ledger |
2.64 °F | of 34,876 August 21–September 20, 2026 |
| day-5 mean absolute temperature error, NBM Forecast Network verification ledger |
3.15 °F | of 32,780 August 21–September 20, 2026 |
| day-7 mean absolute temperature error, NBM Forecast Network verification ledger |
3.72 °F | of 30,292 August 21–September 20, 2026 |
| day-1 mean absolute temperature error, NDFD Forecast Network verification ledger |
2.29 °F | of 33,898 August 21–September 20, 2026 |
| day-3 mean absolute temperature error, NDFD Forecast Network verification ledger |
2.74 °F | of 33,525 August 21–September 20, 2026 |
| day-5 mean absolute temperature error, NDFD Forecast Network verification ledger |
3.27 °F | of 33,069 August 21–September 20, 2026 |
| day-7 mean absolute temperature error, NDFD Forecast Network verification ledger |
3.85 °F | of 19,251 August 21–September 20, 2026 |
- Milepost
- 1147 · laid 2026-09-20T00:25:14Z
- 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
- 3b10a570f04d4a5928338b4acc55332f10a557e805f2a99172a269c6b94fdbd5
- Machine
- JSON