{
  "id": "2026-10-08-atlantic",
  "region": "atlantic",
  "status": "published",
  "draftedAt": "2026-10-08",
  "publishedAt": "2026-10-08",
  "dataThrough": "2026-10-06",
  "headline": "A warm patch persists in the North Atlantic.",
  "value": "+3.4",
  "unit": "\u00b0C",
  "valueLabel": "Above the 1971\u20132000 average",
  "baselineLabel": "1971\u20132000 seasonal average",
  "copy": "Across a patch covering around 350,000 km\u00b2, average surface temperatures stayed at least 2\u00b0C warmer than its seasonal average in the five daily analyses from 2\u20136 October. This is a persistent surface pattern, but its historical rarity and effects on marine life have not been assessed. It is not yet classified as a marine heatwave.",
  "mapHref": "#ao-maps",
  "mapLabel": "Explore the anomaly map",
  "methodsHref": "/data.html#atlantic-sst",
  "source": "NOAA OISST v2.1",
  "sourceUrl": "https://www.ncei.noaa.gov/products/optimum-interpolation-sst",
  "evidence": {
    "searchArea": "Gulf Stream search area",
    "direction": "warm",
    "tiles": 39,
    "areaKm2": 353654,
    "bounds": [
      -60,
      -45,
      40,
      45
    ],
    "latestMeanAnomalyC": 3.41,
    "latestMeanTemperatureC": 21.31,
    "dailyMeanAnomalies": [
      {
        "date": "2026-10-06T12:00:00Z",
        "anomalyC": 3.41
      },
      {
        "date": "2026-10-05T12:00:00Z",
        "anomalyC": 3.29
      },
      {
        "date": "2026-10-04T12:00:00Z",
        "anomalyC": 3.29
      },
      {
        "date": "2026-10-03T12:00:00Z",
        "anomalyC": 3.09
      },
      {
        "date": "2026-10-02T12:00:00Z",
        "anomalyC": 2.92
      }
    ],
    "minimumCommonCoverage": 1.0,
    "representativeTile": [
      -52,
      42
    ],
    "tileCoordinates": [
      [
        -60,
        43
      ],
      [
        -59,
        43
      ],
      [
        -58,
        43
      ],
      [
        -57,
        43
      ],
      [
        -57,
        44
      ],
      [
        -56,
        42
      ],
      [
        -56,
        43
      ],
      [
        -56,
        44
      ],
      [
        -55,
        42
      ],
      [
        -55,
        43
      ],
      [
        -55,
        44
      ],
      [
        -54,
        40
      ],
      [
        -54,
        41
      ],
      [
        -54,
        44
      ],
      [
        -53,
        40
      ],
      [
        -53,
        41
      ],
      [
        -53,
        42
      ],
      [
        -53,
        43
      ],
      [
        -53,
        44
      ],
      [
        -52,
        40
      ],
      [
        -52,
        41
      ],
      [
        -52,
        42
      ],
      [
        -52,
        43
      ],
      [
        -52,
        44
      ],
      [
        -51,
        40
      ],
      [
        -51,
        41
      ],
      [
        -51,
        44
      ],
      [
        -50,
        40
      ],
      [
        -49,
        40
      ],
      [
        -49,
        41
      ],
      [
        -48,
        41
      ],
      [
        -48,
        43
      ],
      [
        -48,
        44
      ],
      [
        -47,
        41
      ],
      [
        -47,
        42
      ],
      [
        -47,
        43
      ],
      [
        -47,
        44
      ],
      [
        -46,
        43
      ],
      [
        -46,
        44
      ]
    ]
  },
  "method": {
    "kind": "research-screening-only",
    "baseline": "1971\u20132000",
    "source": "NOAA OISST v2.1",
    "latestAnalysis": "2026-10-06T12:00:00Z",
    "analysisStatus": "preliminary",
    "retrievedAt": "2026-10-08T02:35:00.851566Z",
    "days": 5,
    "thresholdC": 2.0,
    "minimumTiles": 4,
    "minimumCommonCoverage": 0.9,
    "rank": "largest contiguous area first, then absolute mean anomaly; not statistical significance",
    "searchWindows": {
      "Gulf Stream search area": [
        -65,
        -45,
        32,
        45
      ],
      "Labrador Sea search area": [
        -58,
        -45,
        52,
        61
      ],
      "Northeast Atlantic search area": [
        -35,
        -12,
        45,
        60
      ],
      "Tropical North Atlantic search area": [
        -45,
        -20,
        10,
        25
      ],
      "South Atlantic search area": [
        -30,
        5,
        -35,
        -10
      ],
      "Benguela offshore search area": [
        5,
        12,
        -30,
        -15
      ]
    },
    "limitations": [
      "Named search windows only; not a basin-wide search.",
      "Threshold is an editorial screening choice, not a percentile or heatwave definition.",
      "Persistence is limited to five saved daily analyses; earlier onset is unknown.",
      "Source analyses may be preliminary and are not independent station observations.",
      "No per-cell analysis error or historical daily percentile is present in this saved feed.",
      "Areas use spherical grid-cell geometry; source ice >=15% and missing/invalid SST or anomaly are excluded.",
      "Missing ice fraction is not zero. Such cells are screened only when SST is at least 5 C on every day; this omits colder-water candidates and does not verify absence of ice.",
      "Components stop at search-window boundaries."
    ],
    "sourceSha256": "08bdd22b3336a8792e0093002b44bb4eb20192666b7b763a6c2db4aca029894a"
  },
  "selectionReason": "Largest absolute patch-mean anomaly among candidates covering at least 100,000 km\u00b2. Selection is a screening heuristic, not a historical rarity score.",
  "sourceSha256": "08bdd22b3336a8792e0093002b44bb4eb20192666b7b763a6c2db4aca029894a",
  "editorialAssessment": {
    "analyse": "Ocean-surface temperature averaged +3.41 \u00b0C above the NOAA 1971\u20132000 seasonal baseline across a 353,654 km\u00b2 footprint on 6 October 2026.",
    "evaluate": "The accepted tiles stayed at least +2 \u00b0C above baseline in five consecutive daily analyses. Common valid coverage was 100%. Historical percentiles, formal heatwave criteria and an analysis-error assessment were unavailable; the older baseline should not be read as today\u2019s climate normal.",
    "explain": "The reading identifies a sustained surface-temperature pattern worth following. Local ecosystem effects and causes have not been assessed. No claim of harm or climate attribution is made."
  },
  "reviewedAt": "2026-10-08",
  "archivedInputs": "/briefings/evidence/2026-10-08-atlantic-inputs.json",
  "archivedInputsSha256": "ab8c63599ae6c202d09a749f364141d92e366d45a548e7ed0659aaea5df60210"
}