Phoenix, Arizona Revisions
MILEPOST 1160
Phoenix's forecast for Tuesday has moved 6°F colder
101°F in the 20260918T18:00Z run, 95°F in the 20260920T12:00Z — the 3rd-largest revision of the 3 cities on the roster that moved at all. The current run's 10th-to-90th percentile spread at that hour is 20°F.
Successive cycles do not merely refresh a forecast; they leave a trail. For Tuesday, September 29 at 00Z in Phoenix, that trail runs from 100.9°F in the 20260918T18:00Z cycle to 94.5°F in the 20260920T12:00Z — a move of -6.4°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 Tuesday at 00Z api.weather.city /v1/history (nbm-qmd) |
-6.4 °F | normal 0.0 °F · 3 of 3 8 synoptic cycles |
| 10th-to-90th percentile spread at that hour api.weather.city (nbm-qmd) |
19.6 °F | normal 6.4 °F current run |
- Milepost
- 1160 · laid 2026-09-20T22:26:16Z
- Model
- nbm-qmd · cycle 20260920T12:00Z
- 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
- 7a7c26fe7a2dffce7010d1612d7d07487ead8e62447d07cfee5126c02ddda04a
- Machine
- JSON