Edition 2026-09-25 The Ledger Archive API RSS Weather Trader
Milepost
1213

TheForecast Post

A chronicle of American weather and climate  ·  Friday, 25 September 2026

Denver, Colorado Revisions MILEPOST 1212

Denver's forecast for Monday has moved 11°F colder

73°F in the 20260923T18:00Z run, 61°F in the 20260925T12:00Z — the 2nd-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 32°F.

Successive cycles do not merely refresh a forecast; they leave a trail. For Monday, October 5 at 00Z in Denver, that trail runs from 72.5°F in the 20260923T18:00Z cycle to 61.2°F in the 20260925T12:00Z — a move of -11.3°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 Monday at 00Z
api.weather.city /v1/history (nbm-qmd)
-11.3 °F normal 0.0 °F · 2 of 4
8 synoptic cycles
10th-to-90th percentile spread at that hour
api.weather.city (nbm-qmd)
32.4 °F normal 11.3 °F
current run
Milepost
1212 · laid 2026-09-25T22:25:14Z
Model
nbm-qmd · cycle 20260925T12:00Z
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
60c45f5eeac32afb47ca0257663a2a3fea9d64cc407bb6d755059af2cdb355c0
Machine
JSON