Edition 2026-10-01 The Ledger Archive API RSS Weather Trader
Milepost
1264

TheForecast Post

A chronicle of American weather and climate  ·  Thursday, 1 October 2026

Boston, Massachusetts Revisions MILEPOST 1264

Boston's forecast for Sunday has moved 6°F warmer

54°F in the 20260930T06:00Z run, 61°F in the 20261001T12:00Z — the 3rd-largest revision of the 4 cities on the roster that moved at all. The current run's 10th-to-90th percentile spread at that hour is 19°F.

Successive cycles do not merely refresh a forecast; they leave a trail. For Sunday, October 11 at 18Z in Boston, that trail runs from 54.0°F in the 20260930T06:00Z cycle to 60.5°F in the 20261001T12:00Z — a move of +6.5°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 Sunday at 18Z
api.weather.city /v1/history (nbm-qmd)
6.5 °F normal 0.0 °F · 3 of 4
8 synoptic cycles
10th-to-90th percentile spread at that hour
api.weather.city (nbm-qmd)
18.5 °F normal 6.5 °F
current run
Milepost
1264 · laid 2026-10-01T22:25:14Z
Model
nbm-qmd · cycle 20261001T12:00Z
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
357a933adae8a6b34b3aa94740fedd811df4ed27fd967e38faff857a53bfca86
Machine
JSON