Salt Lake City, Utah Revisions
MILEPOST 1118
Salt Lake City's forecast for Saturday has moved 7°F colder
77°F in the 20260915T06:00Z run, 70°F in the 20260917T00:00Z — the 2nd-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 5°F.
Successive cycles do not merely refresh a forecast; they leave a trail. For Saturday, September 19 at 21Z in Salt Lake City, that trail runs from 77.2°F in the 20260915T06:00Z cycle to 70.0°F in the 20260917T00:00Z — a move of -7.2°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 Saturday at 21Z api.weather.city /v1/history (nbm-qmd) |
-7.2 °F | normal 0.0 °F · 2 of 3 8 synoptic cycles |
| 10th-to-90th percentile spread at that hour api.weather.city (nbm-qmd) |
4.8 °F | normal 7.2 °F current run |
- Milepost
- 1118 · laid 2026-09-17T11:25:16Z
- Model
- nbm-qmd · cycle 20260917T00:00Z
- 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
- f5139e948d04dee026df31a66f8aa319ddc02484853bd97bef46e90c5f3b7d44
- Machine
- JSON