{
  "region": "atlantic",
  "methodsHref": "/data.html#atlantic-sst",
  "source": "World Meteorological Organization; Met Office",
  "sourceUrl": "https://wmo.int/resources/publication-series/global-seasonal-climate-updates/gscu-ndj2026",
  "id": "2026-10-22-atlantic",
  "status": "published",
  "draftedAt": "2026-10-22",
  "plannedPublicationAt": "2026-10-22T11:00:00+01:00",
  "publishedAt": "2026-10-22",
  "reviewedAt": "2026-10-22",
  "evidenceHref": "/data.html#briefing-2026-10-22-atlantic",
  "previousBriefingId": "2026-10-08-atlantic",
  "kind": "seasonal-outlook",
  "dataThrough": "2026-10-21",
  "sourcePublishedAt": "2026-10-21",
  "observationPeriod": null,
  "forecastPeriod": [
    "2026-11-01",
    "2027-01-31"
  ],
  "periodLabel": "Seasonal outlook: November 2026–January 2027",
  "previewDates": "Published 22 Oct 2026 · Outlook issued 21 Oct · Covers Nov 2026–Jan 2027",
  "headline": "El Niño shifts the Atlantic winter outlook.",
  "value": "Dec",
  "unit": "2026",
  "valueLabel": "Forecast El Niño peak",
  "baselineLabel": "Pacific climate driver · Atlantic seasonal outlook",
  "copy": "El Niño is strengthening in the Pacific, with a peak forecast around December. WMO’s 21 October outlook favours above-average tropical Atlantic sea temperatures for November–January. The Met Office says El Niño can raise the likelihood of wetter, windier conditions in the UK during late autumn and early winter. These are seasonal probabilities, not predictions of individual storms; a quieter hurricane season does not mean a storm-free winter.",
  "mapHref": "/data.html#briefing-2026-10-22-atlantic",
  "mapLabel": "Read the seasonal outlook sources",
  "selectionReason": "Owner selected the El Niño outlook for this edition. Distinguish the tropical Pacific driver, forecast tropical Atlantic sea temperatures and probabilistic UK weather context. Keep the measured North Atlantic temperature follow-up archived separately.",
  "editorialAssessment": {
    "analyse": "This is a seasonal outlook, not a new Atlantic observation or fortnightly temperature average. WMO issued its November 2026–January 2027 outlook on 21 October, forecasting further El Niño strengthening towards a December peak and above-normal North and South Tropical Atlantic sea-surface temperatures. The UK weather context is from the Met Office’s 5 October explanation.",
    "evaluate": "WMO reports close agreement among its forecast systems about El Niño strengthening; that is not a probability of a particular UK storm. The December peak is forecast, not an observed maximum. Baselines and regions differ across the source products, so no temperature-anomaly magnitudes are combined here. The Met Office describes shifts in likelihood, with other climate drivers also influencing the weather. No specific storm, cold spell, local flood or ecosystem impact is established by this outlook.",
    "explain": "El Niño develops in the tropical Pacific and can influence Atlantic weather through atmospheric circulation. Fewer tropical hurricanes and wetter, windier winter conditions elsewhere can coexist because hurricanes and winter weather systems are different. This outlook does not attribute our previously measured 40–45°N temperature patch or any individual weather event to El Niño. NOAA documented Isaias becoming a hurricane on 8 October UTC; the season is not hurricane-free."
  },
  "method": {
    "kind": "Independent editorial summary of official seasonal forecasts and interpretation; no new forecast model or numerical anomaly calculation.",
    "limitations": [
      "Forecast peak and seasonal conditions may change.",
      "Seasonal probabilities cannot identify individual storms, landfalls or local impacts.",
      "Warm Atlantic water alone does not establish a marine heatwave or coral bleaching.",
      "Tropical Atlantic forecast conditions are separate from the fixed North Atlantic observation footprint."
    ]
  },
  "providerAvailabilityNote": "Official outlook and interpretation pages checked 22 October. Forecast and interpretation sources rechecked for this edition. Forecast periods are separate from issue dates.",
  "contextSources": [
    {
      "title": "WMO: Global Seasonal Climate Update for November–December–January",
      "url": "https://wmo.int/resources/publication-series/global-seasonal-climate-updates/gscu-ndj2026",
      "publishedAt": "2026-10-21",
      "verifiedAt": "2026-10-22",
      "observationPeriod": "Forecast for November 2026–January 2027",
      "finding": "El Niño is forecast to strengthen towards a December peak. North and South Tropical Atlantic sea-surface temperatures are forecast above normal."
    },
    {
      "title": "Met Office: El Niño and weather headline review",
      "url": "https://www.metoffice.gov.uk/blog/2026/super-el-nino-551-mile-wall-of-rain-and-snow-weather-headline-review",
      "publishedAt": "2026-10-05",
      "verifiedAt": "2026-10-22",
      "observationPeriod": "Late autumn and early winter seasonal context",
      "finding": "El Niño can increase the likelihood of wetter, stormier, generally milder UK conditions early in winter. It does not determine individual events."
    },
    {
      "title": "NOAA: GOES East monitors Hurricane Isaias",
      "url": "https://www.nesdis.noaa.gov/news/noaas-goes-east-satellite-monitors-hurricane-isaias",
      "publishedAt": "2026-10-08",
      "verifiedAt": "2026-10-22",
      "observationPeriod": "7 October CDT / 8 October UTC hurricane formation",
      "finding": "Isaias became the season’s first hurricane on 8 October UTC. NOAA attributes the unusually quiet season partly to El Niño."
    }
  ],
  "archivedInputs": "/briefings/evidence/2026-10-22-atlantic-inputs.json",
  "archivedInputsSha256": "b66f2623182e9a1a9925656298736ea3497d76fc71af6956596eb540e75c57a4",
  "finalSourceCheckRequired": false,
  "reviewRequired": false,
  "wordCount": 67,
  "publicationApprovedAt": "2026-10-22T10:50:26.173432+00:00"
}