Boston, Massachusetts Revisions
MILEPOST 1404
Boston's forecast for Monday has moved 7°F colder
60°F in the 20261014T18:00Z run, 53°F in the 20261016T12:00Z — the 2nd-largest revision of the 4 cities on the roster that moved at all. The current run's 10th-to-90th percentile spread at that hour is 4°F.
Successive cycles do not merely refresh a forecast; they leave a trail. For Monday, October 19 at 21Z in Boston, that trail runs from 60.4°F in the 20261014T18:00Z cycle to 53.1°F in the 20261016T12:00Z — a move of -7.2°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 Monday at 21Z api.weather.city /v1/history (nbm-qmd) |
-7.2 °F | normal 0.0 °F · 2 of 4 8 synoptic cycles |
| 10th-to-90th percentile spread at that hour api.weather.city (nbm-qmd) |
4.5 °F | normal 7.2 °F current run |
- Milepost
- 1404 · laid 2026-10-16T22:25:16Z
- Model
- nbm-qmd · cycle 20261016T12:00Z
- 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
- 0eec5213a465b1c7a872c0bfb0754b9f81eed030783142052f641c71797ea0ce
- Machine
- JSON