Phoenix, Arizona Revisions
MILEPOST 1139
Phoenix's forecast for Sunday has moved 8°F warmer
74°F in the 20260917T06:00Z run, 82°F in the 20260919T00:00Z — the 3rd-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 12°F.
Successive cycles do not merely refresh a forecast; they leave a trail. For Sunday, September 20 at 12Z in Phoenix, that trail runs from 74.1°F in the 20260917T06:00Z cycle to 82.0°F in the 20260919T00:00Z — a move of +7.9°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 Sunday at 12Z api.weather.city /v1/history (nbm-qmd) |
7.9 °F | normal 0.0 °F · 3 of 6 8 synoptic cycles |
| 10th-to-90th percentile spread at that hour api.weather.city (nbm-qmd) |
12 °F | normal 7.9 °F current run |
- Milepost
- 1139 · laid 2026-09-19T10:25:16Z
- Model
- nbm-qmd · cycle 20260919T00:00Z
- 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
- 13db0675c537b7a1e20d65c6e3445cf4fb2f60b09a198383f3fb0df4b7732ac4
- Machine
- JSON