Chicago, Illinois Revisions
MILEPOST 1611
Chicago's forecast for Sunday has moved 8°F colder
55°F in the 20261106T18:00Z run, 47°F in the 20261108T12:00Z — the 3rd-largest revision of the 7 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, November 15 at 18Z in Chicago, that trail runs from 54.7°F in the 20261106T18:00Z cycle to 46.9°F in the 20261108T12:00Z — a move of -7.8°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) |
-7.8 °F | normal 0.0 °F · 3 of 7 8 synoptic cycles |
| 10th-to-90th percentile spread at that hour api.weather.city (nbm-qmd) |
14.2 °F | normal 7.8 °F current run |
- Milepost
- 1611 · laid 2026-11-08T22:25:27Z
- Model
- nbm-qmd · cycle 20261108T12:00Z
- 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
- 2d85c2eb2b28d87c50a1867d6dbd52f27e7695c1ccf44b52883f23ac6c60a3b2
- Machine
- JSON