Boston, Massachusetts Revisions
MILEPOST 1475
Boston's forecast for Wednesday has moved 9°F colder
49°F in the 20261021T00:00Z run, 40°F in the 20261022T18:00Z — the largest revision of any city on the roster. The current run's 10th-to-90th percentile spread at that hour is 8°F.
Successive cycles do not merely refresh a forecast; they leave a trail. For Wednesday, October 28 at 03Z in Boston, that trail runs from 49.2°F in the 20261021T00:00Z cycle to 40.0°F in the 20261022T18:00Z — a move of -9.2°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 Wednesday at 03Z api.weather.city /v1/history (nbm-qmd) |
-9.2 °F | normal 0.0 °F · 1 of 5 8 synoptic cycles |
| 10th-to-90th percentile spread at that hour api.weather.city (nbm-qmd) |
8.5 °F | normal 9.2 °F current run |
- Milepost
- 1475 · laid 2026-10-23T04:25:20Z
- Model
- nbm-qmd · cycle 20261022T18:00Z
- 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
- 299f8b3417a6493826cb1a7b65cb5f4938cbb7992b7a28470ab72fd5e74b963f
- Machine
- JSON