{
  "schema": "cpx.poseidon.forecast-evidence.v1",
  "reviewed_on": "2026-11-13",
  "status": "PUBLIC_RESEARCH_EVIDENCE_NOT_OPERATIONAL_SKILL",
  "policy": "Outcome-only and internally sealed records are never represented as independently authenticated advance forecasts; all evidence statuses are explicit.",
  "seasons": [
    {
      "season": 2024,
      "official_outcome": "Helene and Milton made landfall in Florida in 2024.",
      "original_poseidon_publication": "NOT_RECOVERED",
      "evidence_class": "U",
      "may_claim_forecast_superiority": false,
      "notes": "Official storm outcomes are known. The original Poseidon event forecasts and timestamped issue receipts are not recovered. Replay is a hindcast, not an advance win.",
      "sources": [
        "https://www.nhc.noaa.gov/data/tcr/AL092024_Helene.pdf",
        "https://www.nhc.noaa.gov/data/tcr/AL142024_Milton.pdf"
      ]
    },
    {
      "season": 2025,
      "official_observation": {
        "named_storms": 13,
        "hurricanes": 5,
        "major_hurricanes": 4
      },
      "original_poseidon_publication": "NOT_RECOVERED",
      "evidence_class": "U",
      "may_claim_forecast_superiority": false,
      "notes": "The 2025 NHC result is scored as an official outcome only. No authentic pre-event Poseidon issue receipts recovered.",
      "sources": [
        "https://www.nhc.noaa.gov/data/tcr/index.php?season=2025"
      ]
    },
    {
      "season": 2026,
      "official_observation": {
        "as_of": "2026-11-13T03:00:00Z",
        "named_storms": 10,
        "hurricanes": 1,
        "major_hurricanes": 1,
        "provisional": true
      },
      "original_poseidon_publication": "INTERNALLY_SEALED_VINTAGE_UNAUTHENTICATED",
      "evidence_class": "B",
      "may_claim_forecast_superiority": false,
      "source_name": "POSEIDON_2026_V2_1_EVIDENCE_SEAL.json",
      "source_internal_seal_sha256": "031c1f7fddadfb68fc8cd1d57da3f4c47cd49589a4e7e16ea94f511a222ec951",
      "source_raw_sha256_claim_in_audit": "c4eae9be8fbab832cbdec65a997242c87e3e9533f24870509fb181a3a6a7f131",
      "claimed_forecast_vintage": "2026-10-07",
      "independently_verified_issued_at": null,
      "season_point_forecast": {
        "named_storms": 10,
        "hurricanes": 1,
        "major_hurricanes": 0
      },
      "preliminary_count_error": {
        "named_storms": 0,
        "hurricanes": 0,
        "major_hurricanes": -1
      },
      "storm_case": {
        "name": "Isaias",
        "predicted_peak_winds_kt": [
          85,
          90
        ],
        "actual_peak_winds_kt": 105,
        "peak_error_kt_range": [
          -20,
          -15
        ],
        "intensity_category_predicted": 2,
        "intensity_category_observed": 3,
        "region": "north-central Gulf Coast",
        "regional_result": "Not independently scored for track-point accuracy."
      },
      "notes": "Counts are provisional until Nov 30 and possible post-season revisions. The internally sealed Oct 7 case cannot be called independently pre-event verified without external timestamp evidence; Isaias major-hurricane intensification was missed.",
      "sources": [
        "https://www.nhc.noaa.gov/archive/2026/al09/al092026.discus.012.shtml",
        "https://prod-west-nhc.woc.noaa.gov/data/tcr/index.php?basin=atl&season=2026"
      ]
    },
    {
      "season": 2026,
      "record_type": "ANALYST_UPDATE",
      "claimed_forecast_vintage": "2026-10-10",
      "source_name": "POSEIDON_CPX046_FORWARD_FORECAST_2026-10-10_SEALED.json",
      "evidence_class": "C",
      "independently_verified_issued_at": null,
      "forecast_after_isaias_major_status": true,
      "may_claim_early_prediction_of_isaias_major": false,
      "notes": "Season major-hurricane total was raised to one after Isaias became a major hurricane. This cannot count as an advance prediction of that event. Original production Poseidon model not recovered."
    }
  ],
  "evidence_classes": {
    "A": "Independent pre-event witness of exact unchanged forecast plus explicit issuance/cutoff, then paired outcome and like-for-like comparator.",
    "B": "Recovered self-sealed working record without independent evidence of original issue time. Chronology is an unverified claim.",
    "C": "After-event analyst synthesis or retrospective reconstruction. Excluded from original forward-skill results.",
    "U": "No original forecast artifact; outcome known only. Cannot score."
  },
  "forward_protocol": {
    "issuance": "Publish forecast file and SHA-256 digest in independently dated source and branded public evidence page before observation/target resolution.",
    "timing": "Record forecast issue UTC, knowledge cutoff UTC, first independent public witness UTC and evaluation target UTC. Confirm first_witness < target and no source has observation_time after cutoff.",
    "versions": "Never rewrite issued payload; append a new ID referencing superseded ID. Corrections count as new forecasts with their own issue time.",
    "scoring": "Score every issue, including null events and misses, with identical target, region, lead time, category and timestamp against official NHC issued forecasts, then later post-season best track. Document denominators, uncertainty and calibration.",
    "public_release": "No marketing claims of two-year winning streak or forecast superiority until authenticated cases and independent comparisons meet criteria."
  },
  "safety": "Never use Poseidon research output instead of NHC/NWS warnings or authorized emergency orders."
}