Chicago, Illinois Revisions
MILEPOST 1615
Chicago's forecast for Monday has moved 10°F colder
60°F in the 20261107T00:00Z run, 50°F in the 20261108T18:00Z — the 3rd-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 17°F.
Successive cycles do not merely refresh a forecast; they leave a trail. For Monday, November 16 at 18Z in Chicago, that trail runs from 60.4°F in the 20261107T00:00Z cycle to 50.4°F in the 20261108T18:00Z — a move of -10.0°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 18Z api.weather.city /v1/history (nbm-qmd) |
-10 °F | normal 0.0 °F · 3 of 8 8 synoptic cycles |
| 10th-to-90th percentile spread at that hour api.weather.city (nbm-qmd) |
16.8 °F | normal 10.0 °F current run |
- Milepost
- 1615 · laid 2026-11-09T04:25:25Z
- Model
- nbm-qmd · cycle 20261108T18:00Z
- 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
- d82dacff703d67f5c077fa5ea94710d64fb4fbf48c5b9640e17a43fb65382d52
- Machine
- JSON