Edition 2026-09-21 The Ledger Archive API RSS Weather Trader
Milepost
1164

TheForecast Post

A chronicle of American weather and climate  ·  Monday, 21 September 2026

Minneapolis, Minnesota Revisions MILEPOST 1162

Minneapolis's forecast for Monday has moved 8°F colder

67°F in the 20260919T00:00Z run, 59°F in the 20260920T18:00Z — the 2nd-largest revision of the 5 cities on the roster that moved at all. The current run's 10th-to-90th percentile spread at that hour is 11°F.

Successive cycles do not merely refresh a forecast; they leave a trail. For Monday, September 21 at 21Z in Minneapolis, that trail runs from 66.9°F in the 20260919T00:00Z cycle to 59.0°F in the 20260920T18:00Z — a move of -7.9°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 Monday at 21Z
api.weather.city /v1/history (nbm-qmd)
-7.9 °F normal 0.0 °F · 2 of 5
8 synoptic cycles
10th-to-90th percentile spread at that hour
api.weather.city (nbm-qmd)
11 °F normal 7.9 °F
current run
Milepost
1162 · laid 2026-09-21T04:25:49Z
Model
nbm-qmd · cycle 20260920T18:00Z
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
d8575e068d2047c18a7aebaffbe97de6137d91d2093bf8731ee366a6326ba74d
Machine
JSON