Boston, Massachusetts Revisions
MILEPOST 1517
Boston's forecast for Sunday has moved 11°F colder
46°F in the 20261026T12:00Z run, 35°F in the 20261028T06:00Z — the largest revision of any city on the roster. The current run's 10th-to-90th percentile spread at that hour is 5°F.
Successive cycles do not merely refresh a forecast; they leave a trail. For Sunday, November 1 at 12Z in Boston, that trail runs from 45.6°F in the 20261026T12:00Z cycle to 35.0°F in the 20261028T06:00Z — a move of -10.6°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 12Z api.weather.city /v1/history (nbm-qmd) |
-10.6 °F | normal 0.0 °F · 1 of 9 8 synoptic cycles |
| 10th-to-90th percentile spread at that hour api.weather.city (nbm-qmd) |
5.4 °F | normal 10.6 °F current run |
- Milepost
- 1517 · laid 2026-10-28T16:25:25Z
- Model
- nbm-qmd · cycle 20261028T06:00Z
- 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
- 08bf435c28df221dd3712bbfa8f0c56365c66d731b2316e610e24ff70793ce8e
- Machine
- JSON