Boston, Massachusetts Revisions
MILEPOST 1458
Boston's forecast for Saturday has moved 7°F colder
44°F in the 20261019T18:00Z run, 37°F in the 20261021T12:00Z — the 3rd-largest revision of the 5 cities on the roster that moved at all. 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 Saturday, October 24 at 06Z in Boston, that trail runs from 44.1°F in the 20261019T18:00Z cycle to 37.3°F in the 20261021T12:00Z — a move of -6.8°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 Saturday at 06Z api.weather.city /v1/history (nbm-qmd) |
-6.8 °F | normal 0.0 °F · 3 of 5 8 synoptic cycles |
| 10th-to-90th percentile spread at that hour api.weather.city (nbm-qmd) |
4.9 °F | normal 6.8 °F current run |
- Milepost
- 1458 · laid 2026-10-21T22:25:18Z
- Model
- nbm-qmd · cycle 20261021T12:00Z
- 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
- 79cc0c390911c8e15c8388a88f1535dd2949adc022830a7f579565a19fe94aba
- Machine
- JSON