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

Phoenix, Arizona Revisions MILEPOST 1103

Phoenix's forecast for Thursday has moved 12°F colder

97°F in the 20260914T00:00Z run, 84°F in the 20260915T18:00Z — the 2nd-largest revision of the 5 cities on the roster that moved at all.

Successive cycles do not merely refresh a forecast; they leave a trail. For Thursday, September 17 at 00Z in Phoenix, that trail runs from 96.9°F in the 20260914T00:00Z cycle to 84.4°F in the 20260915T18:00Z — a move of -12.5°F across 8 runs.

This run family does not publish percentiles at this valid time, so the change is reported without a spread to judge it against.

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 Thursday at 00Z
api.weather.city /v1/history (nbm-qmd)
-12.5 °F normal 0.0 °F · 2 of 5
8 synoptic cycles
Milepost
1103 · laid 2026-09-16T04:25:13Z
Model
nbm-qmd · cycle 20260915T18:00Z
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
304dda2f0452118ee8d444cf69055e698442d0cb231d7e51ac9e20ba268c5f16
Machine
JSON