The Ledger The Ledger
MILEPOST 1202
The ledger, through September 25
Mean absolute temperature error runs 2.23°F at day 1 and 3.82°F at day 7, over 520,117 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 26–September 25, 2026.
| Lead | NDFD | NBM | pairs |
|---|---|---|---|
| Day 1 | 2.29 | 2.23 | 71,786 |
| Day 2 | 2.50 | 2.43 | 72,012 |
| Day 3 | 2.76 | 2.65 | 71,713 |
| Day 4 | 3.00 | 2.88 | 71,106 |
| Day 5 | 3.32 | 3.18 | 70,808 |
| Day 6 | 3.65 | 3.51 | 70,275 |
| Day 7 | 4.04 | 3.82 | 56,804 |
| Day 8 | — | 4.13 | 35,613 |
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 35,780 August 26–September 25, 2026 |
| day-3 mean absolute temperature error, NBM Forecast Network verification ledger |
2.65 °F | of 35,781 August 26–September 25, 2026 |
| day-5 mean absolute temperature error, NBM Forecast Network verification ledger |
3.18 °F | of 35,707 August 26–September 25, 2026 |
| day-7 mean absolute temperature error, NBM Forecast Network verification ledger |
3.82 °F | of 35,632 August 26–September 25, 2026 |
| day-1 mean absolute temperature error, NDFD Forecast Network verification ledger |
2.29 °F | of 36,006 August 26–September 25, 2026 |
| day-3 mean absolute temperature error, NDFD Forecast Network verification ledger |
2.76 °F | of 35,932 August 26–September 25, 2026 |
| day-5 mean absolute temperature error, NDFD Forecast Network verification ledger |
3.32 °F | of 35,101 August 26–September 25, 2026 |
| day-7 mean absolute temperature error, NDFD Forecast Network verification ledger |
4.04 °F | of 21,172 August 26–September 25, 2026 |
- Milepost
- 1202 · laid 2026-09-25T00:25:14Z
- 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
- e7e46986227ae059662e861e82f71547fb6963efb8e8db689912c2da2eb417fd
- Machine
- JSON