Boston, Massachusetts Revisions
MILEPOST 1461
Boston's forecast for Sunday has moved 9°F colder
44°F in the 20261020T00:00Z run, 36°F in the 20261021T18:00Z — the 3rd-largest revision of the 9 cities on the roster that moved at all. The current run's 10th-to-90th percentile spread at that hour is 6°F.
Successive cycles do not merely refresh a forecast; they leave a trail. For Sunday, October 25 at 09Z in Boston, that trail runs from 44.3°F in the 20261020T00:00Z cycle to 35.7°F in the 20261021T18:00Z — a move of -8.6°F across 8 runs.
The change is larger than the run's own 10th-to-90th percentile spread — the guidance did not merely narrow, it moved off its previous position.
Model NBM-QMD, via api.weather.city /v1/history. Percentiles are the same run's own.
The numbers in this piece, with what they are measured against
| forecast revision for Sunday at 09Z api.weather.city /v1/history (nbm-qmd) |
-8.6 °F | normal 0.0 °F · 3 of 9 8 synoptic cycles |
| 10th-to-90th percentile spread at that hour api.weather.city (nbm-qmd) |
6.3 °F | normal 8.6 °F current run |
- Milepost
- 1461 · laid 2026-10-22T04:25:17Z
- Model
- nbm-qmd · cycle 20261021T18:00Z
- Desk
- revision v1
- Method
- the same valid time read from successive synoptic cycles; the move is last run minus first run
- Source
- https://api.weather.city/v1/history
- Digest
- 55e3475fc70e483f5610fa937b3a90bdffc4a21640dc2e28aad584f1ef0c92dc
- Machine
- JSON