{
  "title": "Weather forecast issue and verification window data for AI",
  "source_page": "https://fiund.com/industries/forecast-verification-window-data",
  "authorship": "Original fictional Fiund editorial exercise. No actual operating records or third-party source assets are included.",
  "example": {
    "title": "Issue date alone cannot pair a precipitation forecast with observations",
    "context": "An imaginary station has synthetic precipitation amounts in millimeters. The exercise is a time-window join and arithmetic check, not an operational forecast or analysis of real weather-service skill.",
    "records": [
      [
        "FW1",
        "Forecast issues",
        "Issue F-A published day 1 at 00 UTC predicts 12 mm for day 2 00–24 UTC. F-B published day 1 at 12 UTC predicts 5 mm for day 2 12 UTC to day 3 12 UTC."
      ],
      [
        "FW2",
        "Observation O-A",
        "Station DEMO: 10 mm accumulated day 2 00–24 UTC. Quality flag valid for this fictional task."
      ],
      [
        "FW3",
        "Observation O-B",
        "Station DEMO: 7 mm, label 'day 2 noon to day 3 noon'; time zone unspecified. No conversion metadata or interval confirmation supplied."
      ]
    ],
    "question": "Which signed forecast error can be computed as forecast minus observed, and why is the other forecast-observation pairing unresolved?",
    "answer": "FW1's F-A and FW2's O-A share station, units and the day-2 00–24 UTC window, supporting an illustrative signed error of 12 minus 10, or +2 mm. F-B's UTC interval cannot be confidently matched to FW3's noon labels without a time-zone basis. A shared issue date or station does not resolve that interval. Obtain the observation time metadata before calculating F-B's paired error.",
    "failureModes": [
      "Joining forecasts and observations by publication date rather than the valid accumulation window.",
      "Treating unspecified local noon as UTC noon and reporting an apparently precise error."
    ],
    "fields": [
      [
        "Issue timestamp and forecast valid interval",
        "Separates when a forecast was made from what period it covers."
      ],
      [
        "Observation interval and time basis",
        "Supports exact temporal pairing."
      ],
      [
        "Station, unit and quality state",
        "Defines the measurement comparison."
      ]
    ],
    "holdout": "Clarify O-B's interval as UTC and its amount as 7 mm. Require F-B's signed error to become −2 mm while retaining F-A's separate +2 mm result.",
    "boundary": "Use original synthetic readings and dummy stations. Exclude licensed feeds and client forecasts; this single exercise provides no evidence of real-world forecast performance."
  }
}