Edition 2026-09-27 The Ledger Archive API RSS Weather Trader
Milepost
1226

TheForecast Post

A chronicle of American weather and climate  ·  Sunday, 27 September 2026

Denver, Colorado Revisions MILEPOST 1225

Denver's forecast for Sunday has moved 14°F warmer

62°F in the 20260925T06:00Z run, 77°F in the 20260927T00:00Z — the 2nd-largest revision of the 9 cities on the roster that moved at all. The current run's 10th-to-90th percentile spread at that hour is 15°F.

Successive cycles do not merely refresh a forecast; they leave a trail. For Sunday, October 4 at 00Z in Denver, that trail runs from 62.2°F in the 20260925T06:00Z cycle to 76.7°F in the 20260927T00:00Z — a move of +14.5°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 00Z
api.weather.city /v1/history (nbm-qmd)
14.5 °F normal 0.0 °F · 2 of 9
8 synoptic cycles
10th-to-90th percentile spread at that hour
api.weather.city (nbm-qmd)
14.7 °F normal 14.5 °F
current run
Milepost
1225 · laid 2026-09-27T10:25:13Z
Model
nbm-qmd · cycle 20260927T00:00Z
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
05b03d67a449bb5725c4315679e2ff0e367b2f286d615ab78a6cc7f619f64ad6
Machine
JSON