{
 "number": 1401,
 "headline": "Boston's forecast for Monday has moved 8\u00b0F colder",
 "standfirst": "61\u00b0F in the 20261014T12:00Z run, 53\u00b0F in the 20261016T06:00Z \u2014 the 2nd-largest revision of the 3 cities on the roster that moved at all. The current run's 10th-to-90th percentile spread at that hour is 6\u00b0F.",
 "desk": "revision",
 "dateline": {
  "place": "Boston",
  "state": "Massachusetts",
  "lat": 42.36,
  "lon": -71.058,
  "site_key": "newengland",
  "site_name": "Forecast New England",
  "site_url": "https://forecastnewengland.com",
  "accent": null
 },
 "edition": "2026-10-16",
 "published": "2026-10-16T16:25:19Z",
 "updated": null,
 "access": "free",
 "body_html": "<p>Successive cycles do not merely refresh a forecast; they leave a trail. For Monday, October 19 at 21Z in Boston, that trail runs from <span class=\"mono\">61.4\u00b0F</span> in the <span class=\"mono\">20261014T12:00Z</span> cycle to <span class=\"mono\">53.1\u00b0F</span> in the <span class=\"mono\">20261016T06:00Z</span> \u2014 a move of <span class=\"mono\">-8.3\u00b0F</span> across 8 runs.</p><p>The change is larger than the run's own 10th-to-90th percentile spread \u2014 the guidance did not merely narrow, it moved off its previous position.</p><p class=\"note\">Model NBM-QMD, via api.weather.city /v1/history. Percentiles are the same run's own.</p>",
 "body_key": null,
 "teaser_html": "",
 "claims": [
  {
   "text": "forecast revision for Monday at 21Z",
   "value": -8.3,
   "unit": "\u00b0F",
   "normal": 0.0,
   "rank": 2,
   "of": 3,
   "period": "8 synoptic cycles",
   "source": "api.weather.city /v1/history (nbm-qmd)"
  },
  {
   "text": "10th-to-90th percentile spread at that hour",
   "value": 5.8,
   "unit": "\u00b0F",
   "normal": 8.3,
   "rank": null,
   "of": null,
   "period": "current run",
   "source": "api.weather.city (nbm-qmd)"
  }
 ],
 "assets": [],
 "provenance": {
  "built_at": "2026-10-16T16:25:18Z",
  "model": "nbm-qmd",
  "cycle": "20261016T06:00Z",
  "stores": [
   "https://api.weather.city/v1/history"
  ],
  "mint_sha256": null,
  "pairing_rule": "the same valid time read from successive synoptic cycles; the move is last run minus first run",
  "detector": "revision",
  "detector_version": "1",
  "inputs": {
   "city": "Boston",
   "lat": 42.36,
   "lon": -71.058,
   "runs": 8,
   "valid": "2026-10-19T21:00:00",
   "first_run": "20261014T12:00Z",
   "last_run": "20261016T06:00Z"
  }
 },
 "strength": 0.627,
 "tags": [
  "revision",
  "guidance",
  "newengland"
 ],
 "supersedes": null,
 "superseded_by": null,
 "source": "wire",
 "canonical": null,
 "slug": "boston-s-forecast-for-monday-has-moved-8-f-colder",
 "path": "/mp/1401/",
 "url": "https://forecastpost.com/mp/1401/",
 "desk_label": "Revisions",
 "digest": "ca95a8a3029ad2bd679ceb2db8ee89f7e93299532e36fdb249cc8eab544356f8"
}