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Milepost
1108

TheForecast Post

A chronicle of American weather and climate  ·  Wednesday, 16 September 2026

Nashville, Tennessee Revisions MILEPOST 1076

Nashville's forecast for Monday has moved 12°F warmer

61°F in the 20260911T12:00Z run, 72°F in the 20260913T12:00Z — the largest revision of any city on the roster. The current run's 10th-to-90th percentile spread at that hour is 12°F.

Successive cycles do not merely refresh a forecast; they leave a trail. For Monday, September 21 at 12Z in Nashville, that trail runs from 60.8°F in the 20260911T12:00Z cycle to 72.4°F in the 20260913T12:00Z — a move of +11.6°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 12Z
api.weather.city /v1/history (nbm-qmd)
11.6 °F normal 0.0 °F · 1 of 6
8 synoptic cycles
10th-to-90th percentile spread at that hour
api.weather.city (nbm-qmd)
12.1 °F normal 11.6 °F
current run
Milepost
1076 · laid 2026-09-13T22:25:16Z
Model
nbm-qmd · cycle 20260913T12:00Z
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
65c572369c5aaf09f262c20057e9f0839ca63d99d75e66a5b927e687517fa7d0
Machine
JSON