Boston, Massachusetts Revisions
MILEPOST 1455
Boston's forecast for Sunday has moved 8°F colder
44°F in the 20261019T12:00Z run, 36°F in the 20261021T06:00Z — 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 5°F.
Successive cycles do not merely refresh a forecast; they leave a trail. For Sunday, October 25 at 09Z in Boston, that trail runs from 43.8°F in the 20261019T12:00Z cycle to 36.2°F in the 20261021T06:00Z — a move of -7.6°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 Sunday at 09Z api.weather.city /v1/history (nbm-qmd) |
-7.6 °F | normal 0.0 °F · 2 of 4 8 synoptic cycles |
| 10th-to-90th percentile spread at that hour api.weather.city (nbm-qmd) |
5 °F | normal 7.6 °F current run |
- Milepost
- 1455 · laid 2026-10-21T16:25:23Z
- Model
- nbm-qmd · cycle 20261021T06:00Z
- 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
- e602fa84eb2524bc68a0f4e6534f452b8a4ee418ab264f144157e895816c5831
- Machine
- JSON