Edition 2026-09-27 The Ledger Archive API RSS Weather Trader
Milepost
1228

TheForecast Post

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

Dallas, Texas Revisions MILEPOST 1227

Dallas's forecast for Saturday has moved 18°F colder

92°F in the 20260925T12:00Z run, 74°F in the 20260927T06:00Z — the largest revision of any city on the roster. 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 Saturday, October 3 at 18Z in Dallas, that trail runs from 91.7°F in the 20260925T12:00Z cycle to 74.2°F in the 20260927T06:00Z — a move of -17.5°F across 8 runs.

The change is larger than the run's own 10th-to-90th percentile spread — the guidance did not merely narrow, it moved off its previous position.

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 18Z
api.weather.city /v1/history (nbm-qmd)
-17.5 °F normal 0.0 °F · 1 of 11
8 synoptic cycles
10th-to-90th percentile spread at that hour
api.weather.city (nbm-qmd)
14.7 °F normal 17.5 °F
current run
Milepost
1227 · laid 2026-09-27T16:25:11Z
Model
nbm-qmd · cycle 20260927T06:00Z
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
583099241d6626ccddc4e8c11c61b2f09024fa2df49b9b22cd30b1370072ff7b
Machine
JSON