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

Nashville, Tennessee Revisions MILEPOST 1078

Nashville's forecast for Sunday has moved 9°F warmer

84°F in the 20260911T18:00Z run, 94°F in the 20260913T18:00Z — the 2nd-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 14°F.

Successive cycles do not merely refresh a forecast; they leave a trail. For Sunday, September 20 at 18Z in Nashville, that trail runs from 84.4°F in the 20260911T18:00Z cycle to 93.7°F in the 20260913T18:00Z — a move of +9.3°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 Sunday at 18Z
api.weather.city /v1/history (nbm-qmd)
9.3 °F normal 0.0 °F · 2 of 8
8 synoptic cycles
10th-to-90th percentile spread at that hour
api.weather.city (nbm-qmd)
14.1 °F normal 9.3 °F
current run
Milepost
1078 · laid 2026-09-14T04:25:13Z
Model
nbm-qmd · cycle 20260913T18:00Z
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
0f51b81f80c9b29cd9b19478a2930ed82f9446c2adaee06a8bece10819c64f7b
Machine
JSON