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Milepost
1179

TheForecast Post

A chronicle of American weather and climate  ·  Tuesday, 22 September 2026

Salt Lake City, Utah Revisions MILEPOST 1179

Salt Lake City's forecast for Wednesday has moved 7°F colder

76°F in the 20260920T12:00Z run, 69°F in the 20260922T06:00Z — the 3rd-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 16°F.

Successive cycles do not merely refresh a forecast; they leave a trail. For Wednesday, September 30 at 00Z in Salt Lake City, that trail runs from 76.2°F in the 20260920T12:00Z cycle to 68.9°F in the 20260922T06:00Z — a move of -7.2°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 Wednesday at 00Z
api.weather.city /v1/history (nbm-qmd)
-7.2 °F normal 0.0 °F · 3 of 4
8 synoptic cycles
10th-to-90th percentile spread at that hour
api.weather.city (nbm-qmd)
16.1 °F normal 7.2 °F
current run
Milepost
1179 · laid 2026-09-22T17:25:12Z
Model
nbm-qmd · cycle 20260922T06:00Z
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
cfb4c7ea4f2dc0af2c29e6c9de6aaa7abede298716577366eb62412f44dee08a
Machine
JSON