Boston, Massachusetts Revisions
MILEPOST 1242
Boston's forecast for Saturday has moved 8°F warmer
59°F in the 20260927T00:00Z run, 67°F in the 20260929T00:00Z — the 2nd-largest revision of the 6 cities on the roster that moved at all. The current run's 10th-to-90th percentile spread at that hour is 17°F.
Successive cycles do not merely refresh a forecast; they leave a trail. For Saturday, October 3 at 06Z in Boston, that trail runs from 58.7°F in the 20260927T00:00Z cycle to 66.7°F in the 20260929T00:00Z — a move of +7.9°F across 8 runs.
The change sits well inside the run's own spread, which is the guidance converging rather than reversing.
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) |
7.9 °F | normal 0.0 °F · 2 of 6 8 synoptic cycles |
| 10th-to-90th percentile spread at that hour api.weather.city (nbm-qmd) |
16.6 °F | normal 7.9 °F current run |
- Milepost
- 1242 · laid 2026-09-29T10:25:14Z
- Model
- nbm-qmd · cycle 20260929T00:00Z
- 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
- 4794202b3e3ad11d9e80512dbbbfdd8285309cd37752681913217a8f097ea74e
- Machine
- JSON