{
  "claim_note": "Historical targets are authentic NOAA observations, model baseline is a retrospective simulation, not a live issued Poseidon prediction. No street-scale flood inference.",
  "frozen_forward_2027_2030_claim": null,
  "independent_forecast_skill_proven": false,
  "model": "fixed prior-30-year climatological mean, min 20 completed years",
  "observation_vintage": "CURRENT_REVISED_BEST_TRACK",
  "official_noaa_derived_sha256": "b3f567245e8dff06903f98e1c8ca95ae7b0f15cbcdf730dde5203500bda32acd",
  "official_noaa_raw_sha256": "75202780ce56c8458f16fbef5fb8a026b99b00878dbb95c458211b3e6ef125b4",
  "real_noaa_observations_used": true,
  "replay_class": "RETROSPECTIVE_RECONSTRUCTION_NOT_PRE_EVENT_FORECAST",
  "result": {
    "ace_approx": {
      "1871-2025": {
        "bias_pred_minus_observed": -7.9756,
        "complete_years_only": true,
        "first_season": 1871,
        "last_season": 2025,
        "mae": 40.9504,
        "mean_model": 87.9267,
        "mean_observed": 95.9023,
        "n": 155,
        "rmse": 54.6641
      },
      "1980-2025": {
        "bias_pred_minus_observed": -15.502,
        "complete_years_only": true,
        "first_season": 1980,
        "last_season": 2025,
        "mae": 48.0037,
        "mean_model": 98.614,
        "mean_observed": 114.116,
        "n": 46,
        "rmse": 60.9004
      },
      "2004-2023": {
        "bias_pred_minus_observed": -21.448,
        "complete_years_only": true,
        "first_season": 2004,
        "last_season": 2023,
        "mae": 50.0313,
        "mean_model": 110.2746,
        "mean_observed": 131.7226,
        "n": 20,
        "rmse": 63.7341
      }
    },
    "csu_april_named_storms_2004_2023": {
      "baseline_mae": 4.9,
      "claim_noaa_or_csu_superiority": false,
      "csu_source_limit": "Manual CSU archived historical table; individual original issue timestamps not authenticated",
      "evidence_class": "RETROSPECTIVE_DIAGNOSTIC",
      "independently_verified": false,
      "matched_seasons_n": 20,
      "note": "resampling by season, historical archive/revisions and release gates still require audit",
      "paired_bootstrap_95ci": [
        -1.4701,
        1.0066
      ],
      "paired_mae_improvement": -0.2433,
      "poseidon_mae": 5.1433,
      "same_era_note": "Contemporaneous forecast vintages are not reproduced by modern revised NOAA target record",
      "win_supported": false,
      "years": [
        2004,
        2005,
        2006,
        2007,
        2008,
        2009,
        2010,
        2011,
        2012,
        2013,
        2014,
        2015,
        2016,
        2017,
        2018,
        2019,
        2020,
        2021,
        2022,
        2023
      ]
    },
    "hurricanes": {
      "1871-2025": {
        "bias_pred_minus_observed": -0.2602,
        "complete_years_only": true,
        "first_season": 1871,
        "last_season": 2025,
        "mae": 2.0166,
        "mean_model": 5.4237,
        "mean_observed": 5.6839,
        "n": 155,
        "rmse": 2.612
      },
      "1980-2025": {
        "bias_pred_minus_observed": -0.6638,
        "complete_years_only": true,
        "first_season": 1980,
        "last_season": 2025,
        "mae": 2.4812,
        "mean_model": 6.184,
        "mean_observed": 6.8478,
        "n": 46,
        "rmse": 3.0645
      },
      "2004-2023": {
        "bias_pred_minus_observed": -1.1167,
        "complete_years_only": true,
        "first_season": 2004,
        "last_season": 2023,
        "mae": 2.5901,
        "mean_model": 6.6333,
        "mean_observed": 7.75,
        "n": 20,
        "rmse": 3.513
      }
    },
    "major_hurricanes": {
      "1871-2025": {
        "bias_pred_minus_observed": -0.2873,
        "complete_years_only": true,
        "first_season": 1871,
        "last_season": 2025,
        "mae": 1.2185,
        "mean_model": 1.8418,
        "mean_observed": 2.129,
        "n": 155,
        "rmse": 1.5985
      },
      "1980-2025": {
        "bias_pred_minus_observed": -0.5087,
        "complete_years_only": true,
        "first_season": 1980,
        "last_season": 2025,
        "mae": 1.4058,
        "mean_model": 2.4044,
        "mean_observed": 2.913,
        "n": 46,
        "rmse": 1.8336
      },
      "2004-2023": {
        "bias_pred_minus_observed": -0.775,
        "complete_years_only": true,
        "first_season": 2004,
        "last_season": 2023,
        "mae": 1.5984,
        "mean_model": 2.775,
        "mean_observed": 3.55,
        "n": 20,
        "rmse": 2.1037
      }
    },
    "named_storms": {
      "1871-2025": {
        "bias_pred_minus_observed": -0.9491,
        "complete_years_only": true,
        "first_season": 1871,
        "last_season": 2025,
        "mae": 3.1472,
        "mean_model": 9.7025,
        "mean_observed": 10.6516,
        "n": 155,
        "rmse": 4.1538
      },
      "1980-2025": {
        "bias_pred_minus_observed": -1.687,
        "complete_years_only": true,
        "first_season": 1980,
        "last_season": 2025,
        "mae": 4.0232,
        "mean_model": 11.9,
        "mean_observed": 13.587,
        "n": 46,
        "rmse": 5.2585
      },
      "2004-2023": {
        "bias_pred_minus_observed": -3.9466,
        "complete_years_only": true,
        "first_season": 2004,
        "last_season": 2023,
        "mae": 5.1433,
        "mean_model": 12.7034,
        "mean_observed": 16.65,
        "n": 20,
        "rmse": 6.7053
      }
    }
  },
  "schema": "cpx.poseidon.official-noaa-historical-replay.v1",
  "season_truth_span": [
    1851,
    2025
  ],
  "source_revision_date": "2026-09-23",
  "source_url": "https://www.nhc.noaa.gov/data/hurdat/hurdat2-1851-2025-092326.txt"
}