# The Forecast Post

> A chronicle of American weather and climate. A daily chronicle of American weather and climate, published
> from the Forecast Network's own data: 45 state and metro
> sites, a shared point API, and a permanent forecast-verification ledger.

The Post is a record rather than a feed. Each entry is a **milepost** — a number
issued once and never reissued, with a dateline and a date. Corrections do not
overwrite an entry; they lay the next milepost and link back.

## What makes this citable

Every number published here carries the thing that makes it readable: a normal to
compare against, a rank within a stated period of record, or the denominator it
was drawn from. This is enforced when the page is built, not left to the writer.
If you are summarising a story from this site, those values are available as
structured fields — please cite them rather than restating the bare number.

Each milepost also carries provenance: the model and cycle it was read from, the
pairing rule used, and the source stores. Where a forecast-mint object exists, its
SHA-256 is given, so the numbers a story was written from can be recovered exactly.

## Machine-readable endpoints

- [API index](https://forecastpost.com/api): all endpoints
- [Milepost index](https://forecastpost.com/api/v1/mileposts.json): the chronicle, newest first
- [One milepost](https://forecastpost.com/api/v1/mp/1.json): claims and provenance included
- [Skill ledger](https://forecastpost.com/api/v1/ledger.json): forecast error by model and lead
- [JSON Feed](https://forecastpost.com/feed.json) · [RSS](https://forecastpost.com/feed.xml) · [Atom](https://forecastpost.com/atom.xml)
- [OpenAPI](https://forecastpost.com/openapi.json)

## Desks

- **The Record** — Where today sits in the period of record.
- **The Ledger** — What was forecast, what happened, and the difference.
- **Revisions** — Forecasts that moved, and by how much.
- **Disagreement** — Where the guidance does not agree with itself.
- **Tropics** — The basins, their systems, and their obituaries.
- **Winter** — Snow, ice, and the cold season's firsts and lasts.
- **Hazards** — Warnings, weighted by how unusual they are where issued.
- **The Almanac** — On this date, and the long view.
- **Obituaries** — Storms that died, and what they were forecast to be.
- **Markets** — Degree days, crops, energy, and the weather in the line.
- **Letters** — Readers' questions, answered with the data.
- **Notebook** — The editor, at length.

## Access

Most mileposts are free. Some carry writing first published to
Weather Trader (https://weather.substack.com) for paid subscribers; for those, this
site publishes the headline, standfirst, dateline, claims and provenance, and a
teaser — never the full body, at any endpoint. `access: "members"` in the API
marks them.

## Recent

- [MP 1108: Nashville's forecast for Monday has moved 9°F warmer](https://forecastpost.com/mp/1108/): 87°F in the 20260914T12:00Z run, 96°F in the 20260916T06:00Z — 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 11°F.
- [MP 1107: Minneapolis's forecast for Monday has moved 12°F colder](https://forecastpost.com/mp/1107/): 74°F in the 20260914T12:00Z run, 62°F in the 20260916T06:00Z — the largest revision of any city on the roster. The current run's 10th-to-90th percentile spread at that hour is 12°F.
- [MP 1106: Salt Lake City's forecast for Saturday has moved 8°F warmer](https://forecastpost.com/mp/1106/): 73°F in the 20260914T12:00Z run, 81°F in the 20260916T00:00Z — the 3rd-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 12°F.
- [MP 1105: Kansas City's forecast for Friday has moved 9°F colder](https://forecastpost.com/mp/1105/): 77°F in the 20260913T18:00Z run, 68°F in the 20260915T18:00Z — the 3rd-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 15°F.
- [MP 1104: New York's forecast for Tuesday has moved 8°F colder](https://forecastpost.com/mp/1104/): 74°F in the 20260914T00:00Z run, 67°F in the 20260915T18:00Z — the 3rd-largest revision of the 5 cities on the roster that moved at all.
- [MP 1103: Phoenix's forecast for Thursday has moved 12°F colder](https://forecastpost.com/mp/1103/): 97°F in the 20260914T00:00Z run, 84°F in the 20260915T18:00Z — the 2nd-largest revision of the 5 cities on the roster that moved at all.
- [MP 1102: Minneapolis's forecast for Friday has moved 14°F colder](https://forecastpost.com/mp/1102/): 75°F in the 20260914T00:00Z run, 62°F in the 20260915T18:00Z — the largest revision of any city on the roster.
- [MP 1101: The ledger, through September 16](https://forecastpost.com/mp/1101/): Mean absolute temperature error runs 2.23°F at day 1 and 3.65°F at day 7, over 432,892 settled forecast-observation pairs.
- [MP 1100: New York's forecast for Saturday has moved 8°F colder](https://forecastpost.com/mp/1100/): 70°F in the 20260913T18:00Z run, 62°F in the 20260915T12:00Z — the 3rd-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 9°F.
- [MP 1099: Guidance has run 2.5°F warm at NBG for a month](https://forecastpost.com/mp/1099/): The mean signed residual across 5,707 pairs is +2.54°F, against -0.03°F averaged over all 77 stations with enough samples to score. A bias is not an error the reader can ignore — it is one they can correct for.
- [MP 1098: Minneapolis's forecast for Friday has moved 11°F colder](https://forecastpost.com/mp/1098/): 70°F in the 20260913T18:00Z run, 60°F in the 20260915T12:00Z — 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 14°F.
- [MP 1097: Phoenix's forecast for Thursday has moved 13°F colder](https://forecastpost.com/mp/1097/): 98°F in the 20260913T18:00Z run, 85°F in the 20260915T12:00Z — the largest revision of any city on the roster. The current run's 10th-to-90th percentile spread at that hour is 16°F.
- [MP 1096: Chicago's forecast for Saturday has moved 7°F warmer](https://forecastpost.com/mp/1096/): 71°F in the 20260913T12:00Z run, 78°F in the 20260915T06:00Z — the 3rd-largest revision of the 5 cities on the roster that moved at all. The current run's 10th-to-90th percentile spread at that hour is 20°F.
- [MP 1095: Minneapolis's forecast for Friday has moved 13°F colder](https://forecastpost.com/mp/1095/): 75°F in the 20260913T12:00Z run, 62°F in the 20260915T06:00Z — the 2nd-largest revision of the 5 cities on the roster that moved at all. The current run's 10th-to-90th percentile spread at that hour is 20°F.
- [MP 1094: Phoenix's forecast for Thursday has moved 14°F colder](https://forecastpost.com/mp/1094/): 99°F in the 20260913T12:00Z run, 85°F in the 20260915T06:00Z — the largest revision of any city on the roster. The current run's 10th-to-90th percentile spread at that hour is 15°F.
- [MP 1093: Kansas City's forecast for Saturday has moved 13°F warmer](https://forecastpost.com/mp/1093/): 70°F in the 20260913T00:00Z run, 84°F in the 20260915T00:00Z — the largest revision of any city on the roster. The current run's 10th-to-90th percentile spread at that hour is 15°F.
- [MP 1092: Chicago's forecast for Saturday has moved 8°F warmer](https://forecastpost.com/mp/1092/): 71°F in the 20260913T06:00Z run, 79°F in the 20260915T00:00Z — 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 16°F.
- [MP 1091: Phoenix's forecast for Thursday has moved 9°F colder](https://forecastpost.com/mp/1091/): 100°F in the 20260913T06:00Z run, 91°F in the 20260915T00:00Z — the 2nd-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 16°F.
- [MP 1090: Minneapolis's forecast for Friday has moved 9°F colder](https://forecastpost.com/mp/1090/): 74°F in the 20260913T06:00Z run, 65°F in the 20260915T00:00Z — the largest revision of any city on the roster. The current run's 10th-to-90th percentile spread at that hour is 20°F.
- [MP 1089: Denver's forecast for Sunday has moved 9°F colder](https://forecastpost.com/mp/1089/): 78°F in the 20260912T18:00Z run, 69°F in the 20260914T18:00Z — the 3rd-largest revision of the 9 cities on the roster that moved at all. The current run's 10th-to-90th percentile spread at that hour is 11°F.
- [MP 1088: The ledger, through September 15](https://forecastpost.com/mp/1088/): Mean absolute temperature error runs 2.23°F at day 1 and 3.61°F at day 7, over 415,341 settled forecast-observation pairs.
- [MP 1087: Minneapolis's forecast for Saturday has moved 9°F warmer](https://forecastpost.com/mp/1087/): 54°F in the 20260912T12:00Z run, 64°F in the 20260914T12:00Z — the 3rd-largest revision of the 9 cities on the roster that moved at all. The current run's 10th-to-90th percentile spread at that hour is 11°F.
- [MP 1086: Chicago's forecast for Saturday has moved 12°F warmer](https://forecastpost.com/mp/1086/): 70°F in the 20260912T12:00Z run, 82°F in the 20260914T12:00Z — the 2nd-largest revision of the 9 cities on the roster that moved at all. The current run's 10th-to-90th percentile spread at that hour is 19°F.
- [MP 1085: Kansas City's forecast for Saturday has moved 17°F warmer](https://forecastpost.com/mp/1085/): 69°F in the 20260912T18:00Z run, 86°F in the 20260914T12:00Z — the largest revision of any city on the roster. The current run's 10th-to-90th percentile spread at that hour is 19°F.
- [MP 1084: Kansas City's forecast for Saturday has moved 14°F warmer](https://forecastpost.com/mp/1084/): 71°F in the 20260912T12:00Z run, 85°F in the 20260914T06:00Z — the largest revision of any city on the roster. The current run's 10th-to-90th percentile spread at that hour is 19°F.