Boston, Massachusetts Revisions
MILEPOST 1522
Boston's forecast for Monday has moved 9°F colder
52°F in the 20261027T00:00Z run, 43°F in the 20261028T18:00Z — the largest revision of any city on the roster. The current run's 10th-to-90th percentile spread at that hour is 11°F.
Successive cycles do not merely refresh a forecast; they leave a trail. For Monday, November 2 at 12Z in Boston, that trail runs from 52.1°F in the 20261027T00:00Z cycle to 42.9°F in the 20261028T18:00Z — a move of -9.2°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 Monday at 12Z api.weather.city /v1/history (nbm-qmd) |
-9.2 °F | normal 0.0 °F · 1 of 8 8 synoptic cycles |
| 10th-to-90th percentile spread at that hour api.weather.city (nbm-qmd) |
10.8 °F | normal 9.2 °F current run |
- Milepost
- 1522 · laid 2026-10-29T04:25:27Z
- Model
- nbm-qmd · cycle 20261028T18:00Z
- 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
- ed819dc48fc9cca3f45170af55c84191b6713cc2e9182942b60e328739777927
- Machine
- JSON