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Milepost
1185

TheForecast Post

A chronicle of American weather and climate  ·  Wednesday, 23 September 2026

New York, New York Revisions MILEPOST 1184

New York's forecast for Friday has moved 9°F warmer

60°F in the 20260921T00:00Z run, 69°F in the 20260922T18:00Z — the 2nd-largest revision of the 6 cities on the roster that moved at all. The current run's 10th-to-90th percentile spread at that hour is 17°F.

Successive cycles do not merely refresh a forecast; they leave a trail. For Friday, September 25 at 18Z in New York, that trail runs from 60.1°F in the 20260921T00:00Z cycle to 68.7°F in the 20260922T18:00Z — a move of +8.6°F across 8 runs.

The change sits well inside the run's own spread, which is the guidance converging rather than reversing.

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 Friday at 18Z
api.weather.city /v1/history (nbm-qmd)
8.6 °F normal 0.0 °F · 2 of 6
8 synoptic cycles
10th-to-90th percentile spread at that hour
api.weather.city (nbm-qmd)
17.2 °F normal 8.6 °F
current run
Milepost
1184 · laid 2026-09-23T04:25:16Z
Model
nbm-qmd · cycle 20260922T18:00Z
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
4bd09c6d9bd154ea531dad66289715d035a1da74f15501e8d81977f410c925f1
Machine
JSON