Seattle, Washington Revisions
MILEPOST 1148
Seattle's forecast for Friday has moved 7°F colder
69°F in the 20260918T00:00Z run, 61°F in the 20260919T18:00Z — the largest revision of any city on the roster. The current run's 10th-to-90th percentile spread at that hour is 8°F.
Successive cycles do not merely refresh a forecast; they leave a trail. For Friday, September 25 at 00Z in Seattle, that trail runs from 68.6°F in the 20260918T00:00Z cycle to 61.1°F in the 20260919T18:00Z — a move of -7.5°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 Friday at 00Z api.weather.city /v1/history (nbm-qmd) |
-7.5 °F | normal 0.0 °F · 1 of 3 8 synoptic cycles |
| 10th-to-90th percentile spread at that hour api.weather.city (nbm-qmd) |
7.8 °F | normal 7.5 °F current run |
- Milepost
- 1148 · laid 2026-09-20T04:25:19Z
- Model
- nbm-qmd · cycle 20260919T18:00Z
- 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
- a2b92e9d6a5a3e1f50d746a2a70a5c2d04fb40bd5874adbd1450d02cb7e2168d
- Machine
- JSON