The Ledger The Ledger
MILEPOST 1173
The ledger, through September 22
Mean absolute temperature error runs 2.22°F at day 1 and 3.78°F at day 7, over 497,875 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 23–September 22, 2026.
| Lead | NDFD | NBM | pairs |
|---|---|---|---|
| Day 1 | 2.28 | 2.22 | 69,794 |
| Day 2 | 2.49 | 2.42 | 69,496 |
| Day 3 | 2.74 | 2.63 | 68,898 |
| Day 4 | 2.98 | 2.86 | 68,589 |
| Day 5 | 3.31 | 3.16 | 68,520 |
| Day 6 | 3.61 | 3.49 | 67,532 |
| Day 7 | 3.94 | 3.78 | 53,474 |
| Day 8 | — | 4.08 | 31,572 |
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 |
2.22 °F | of 35,048 August 23–September 22, 2026 |
| day-3 mean absolute temperature error, NBM Forecast Network verification ledger |
2.63 °F | of 34,976 August 23–September 22, 2026 |
| day-5 mean absolute temperature error, NBM Forecast Network verification ledger |
3.16 °F | of 34,975 August 23–September 22, 2026 |
| day-7 mean absolute temperature error, NBM Forecast Network verification ledger |
3.78 °F | of 32,712 August 23–September 22, 2026 |
| day-1 mean absolute temperature error, NDFD Forecast Network verification ledger |
2.28 °F | of 34,746 August 23–September 22, 2026 |
| day-3 mean absolute temperature error, NDFD Forecast Network verification ledger |
2.74 °F | of 33,922 August 23–September 22, 2026 |
| day-5 mean absolute temperature error, NDFD Forecast Network verification ledger |
3.31 °F | of 33,545 August 23–September 22, 2026 |
| day-7 mean absolute temperature error, NDFD Forecast Network verification ledger |
3.94 °F | of 20,762 August 23–September 22, 2026 |
- Milepost
- 1173 · laid 2026-09-22T00:25:14Z
- 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
- 43aae3ffea26308bea4f52507d7765c543002e4e9bba334cd83b40c8760b6cc0
- Machine
- JSON