Edition 2026-09-16 The Ledger Archive API RSS Weather Trader
Milepost
1108

TheForecast Post

A chronicle of American weather and climate  ·  Wednesday, 16 September 2026

Denver, Colorado Revisions MILEPOST 1050

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

81°F in the 20260909T00:00Z run, 70°F in the 20260910T18:00Z — the 3rd-largest revision of the 8 cities on the roster that moved at all. The current run's 10th-to-90th percentile spread at that hour is 18°F.

Successive cycles do not merely refresh a forecast; they leave a trail. For Wednesday, September 16 at 00Z in Denver, that trail runs from 81.0°F in the 20260909T00:00Z cycle to 70.1°F in the 20260910T18:00Z — a move of -10.9°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 Wednesday at 00Z
api.weather.city /v1/history (nbm-qmd)
-10.9 °F normal 0.0 °F · 3 of 8
8 synoptic cycles
10th-to-90th percentile spread at that hour
api.weather.city (nbm-qmd)
18.3 °F normal 10.9 °F
current run
Milepost
1050 · laid 2026-09-11T04:25:13Z
Model
nbm-qmd · cycle 20260910T18:00Z
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
8e46399af0a6ffc645a3f6005f0d3534d061e2e01ae7cd08831f87bc07ebe390
Machine
JSON