Edition 2026-09-27 The Ledger Archive API RSS Weather Trader
Milepost
1223

TheForecast Post

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

Dallas, Texas Revisions MILEPOST 1222

Dallas's forecast for Saturday has moved 14°F colder

95°F in the 20260925T12:00Z run, 81°F in the 20260926T18:00Z — the largest revision of any city on the roster. The current run's 10th-to-90th percentile spread at that hour is 21°F.

Successive cycles do not merely refresh a forecast; they leave a trail. For Saturday, October 3 at 21Z in Dallas, that trail runs from 95.1°F in the 20260925T12:00Z cycle to 81.4°F in the 20260926T18:00Z — a move of -13.7°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 Saturday at 21Z
api.weather.city /v1/history (nbm-qmd)
-13.7 °F normal 0.0 °F · 1 of 10
8 synoptic cycles
10th-to-90th percentile spread at that hour
api.weather.city (nbm-qmd)
21.2 °F normal 13.7 °F
current run
Milepost
1222 · laid 2026-09-27T04:25:13Z
Model
nbm-qmd · cycle 20260926T18:00Z
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
bd30ea569f105770eda5c9fc05b1e4d9a82651a895f82e3b49fa2000e09c3595
Machine
JSON