Boston, Massachusetts Revisions
MILEPOST 1427
Boston's forecast for Saturday has moved 9°F colder
49°F in the 20261016T12:00Z run, 40°F in the 20261018T06:00Z — the 3rd-largest revision of the 7 cities on the roster that moved at all. The current run's 10th-to-90th percentile spread at that hour is 9°F.
Successive cycles do not merely refresh a forecast; they leave a trail. For Saturday, October 24 at 12Z in Boston, that trail runs from 48.6°F in the 20261016T12:00Z cycle to 40.0°F in the 20261018T06:00Z — a move of -8.6°F across 8 runs.
The change is about half the run's 10th-to-90th percentile spread, so the earlier forecast is still inside the current range of outcomes.
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 12Z api.weather.city /v1/history (nbm-qmd) |
-8.6 °F | normal 0.0 °F · 3 of 7 8 synoptic cycles |
| 10th-to-90th percentile spread at that hour api.weather.city (nbm-qmd) |
9.2 °F | normal 8.6 °F current run |
- Milepost
- 1427 · laid 2026-10-18T16:25:17Z
- Model
- nbm-qmd · cycle 20261018T06:00Z
- 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
- 5b4c6eca20474b99186719d2722927c362420c23a37d8afc0fb373425234231e
- Machine
- JSON