{"abstract":"Overcast days receive unstable daytime classes.","category":"Weather index computation","checks":8,"contract":"Wind class: <2, <3, <5, <6, >=6 (index 0..4). 8 octas returns \"D\" day or night. Day: tables by insolation strong [A,A-B,B,C,C], moderate [A-B,B,B-C,C-D,D], slight [B,C,C,D,D]; unknown insolation returns None. Night: >=4 octas [E,E,D,D,D], <=3 octas [F,F,E,D,D].","contract_signature":"wind_ms, is_day, insolation, octas","evaluation_group":"w2-weather_index_computation-pasquill-stability","failed_approach":"Applying the override from 7 octas neutralises broken-cloud nights.","family":"w2-weather_index_computation-pasquill-stability-overcast-neutral-override","id":"FA-71291","implementations":{"attempt":{"sha256":"a7c4a6b23e3935de3e36b1effe3d8be5d2674a2f68fd4073e8a88d6c887589d0","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(wind_ms, is_day, insolation, octas):\n    day = {\"strong\": [\"A\", \"A-B\", \"B\", \"C\", \"C\"],\n           \"moderate\": [\"A-B\", \"B\", \"B-C\", \"C-D\", \"D\"],\n           \"slight\": [\"B\", \"C\", \"C\", \"D\", \"D\"]}\n    thin = [\"E\", \"E\", \"D\", \"D\", \"D\"]\n    clear = [\"F\", \"F\", \"E\", \"D\", \"D\"]\n    if octas >= 7:\n        return \"D\"\n    i = 0 if wind_ms < 2 else 1 if wind_ms < 3 else 2 if wind_ms < 5 else 3 if wind_ms < 6 else 4\n    if is_day:\n        if insolation not in day:\n            return None\n        return day[insolation][i]\n    return (thin if octas >= 4 else clear)[i]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['wind 1.0 day strong 2 octas', [1.0, True, 'strong', 2], 'A'], ['wind 1.0 day moderate 5 octas', [1.0, True, 'moderate', 5], 'A-B'], ['wind 1.0 day slight 8 octas', [1.0, True, 'slight', 8], 'D'], ['wind 1.0 day slight 3 octas', [1.0, True, 'slight', 3], 'B'], ['wind 1.0 night None 3 octas', [1.0, False, None, 3], 'F'], ['wind 1.0 night None 4 octas', [1.0, False, None, 4], 'E'], ['wind 1.0 night None 8 octas', [1.0, False, None, 8], 'D'], ['wind 1.0 day strong 7 octas', [1.0, True, 'strong', 7], 'A']], [['wind 1.0 day overcast-ish 4 octas', [1.0, True, 'overcast-ish', 4], None], ['wind 1.0 night None 7 octas', [1.0, False, None, 7], 'E'], ['wind 1.0 day strong 7 octas', [1.0, True, 'strong', 7], 'A'], ['wind 1.9 day strong 2 octas', [1.9, True, 'strong', 2], 'A'], ['wind 1.9 day moderate 5 octas', [1.9, True, 'moderate', 5], 'A-B'], ['wind 1.9 day slight 8 octas', [1.9, True, 'slight', 8], 'D'], ['wind 2.9 day slight 8 octas', [2.9, True, 'slight', 8], 'D'], ['wind 2.9 night None 7 octas', [2.9, False, None, 7], 'E']], [['wind 1.0 day slight 8 octas', [1.0, True, 'slight', 8], 'D'], ['wind 1.9 night None 3 octas', [1.9, False, None, 3], 'F'], ['wind 1.9 night None 4 octas', [1.9, False, None, 4], 'E'], ['wind 1.9 night None 8 octas', [1.9, False, None, 8], 'D'], ['wind 1.9 day overcast-ish 4 octas', [1.9, True, 'overcast-ish', 4], None], ['wind 1.9 night None 7 octas', [1.9, False, None, 7], 'E'], ['wind 1.9 day strong 7 octas', [1.9, True, 'strong', 7], 'A'], ['wind 5.9 day strong 7 octas', [5.9, True, 'strong', 7], 'C']], [['wind 1.9 night None 7 octas', [1.9, False, None, 7], 'E'], ['wind 2.0 day moderate 5 octas', [2.0, True, 'moderate', 5], 'B'], ['wind 2.0 day slight 8 octas', [2.0, True, 'slight', 8], 'D'], ['wind 2.0 day slight 3 octas', [2.0, True, 'slight', 3], 'C'], ['wind 2.0 night None 3 octas', [2.0, False, None, 3], 'F'], ['wind 2.0 night None 4 octas', [2.0, False, None, 4], 'E'], ['wind 2.0 night None 8 octas', [2.0, False, None, 8], 'D'], ['wind 2.9 day slight 8 octas', [2.9, True, 'slight', 8], 'D']], [['wind 1.0 day slight 8 octas', [1.0, True, 'slight', 8], 'D'], ['wind 2.0 night None 7 octas', [2.0, False, None, 7], 'E'], ['wind 2.0 day strong 7 octas', [2.0, True, 'strong', 7], 'A-B'], ['wind 2.9 day strong 2 octas', [2.9, True, 'strong', 2], 'A-B'], ['wind 2.9 day moderate 5 octas', [2.9, True, 'moderate', 5], 'B'], ['wind 2.9 day slight 8 octas', [2.9, True, 'slight', 8], 'D'], ['wind 2.9 day slight 3 octas', [2.9, True, 'slight', 3], 'C'], ['wind 2.9 day strong 7 octas', [2.9, True, 'strong', 7], 'A-B']]]\nfor label, args, expected in fixtures[N - 1]:\n    check(label, solve(*args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"679a70cca1cb748e3829d07015305075a2d4afc9868eb508d0c3e4d2ee495e10","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(wind_ms, is_day, insolation, octas):\n    day = {\"strong\": [\"A\", \"A-B\", \"B\", \"C\", \"C\"],\n           \"moderate\": [\"A-B\", \"B\", \"B-C\", \"C-D\", \"D\"],\n           \"slight\": [\"B\", \"C\", \"C\", \"D\", \"D\"]}\n    thin = [\"E\", \"E\", \"D\", \"D\", \"D\"]\n    clear = [\"F\", \"F\", \"E\", \"D\", \"D\"]\n    if octas == 8 and not is_day:\n        return \"D\"\n    i = 0 if wind_ms < 2 else 1 if wind_ms < 3 else 2 if wind_ms < 5 else 3 if wind_ms < 6 else 4\n    if is_day:\n        if insolation not in day:\n            return None\n        return day[insolation][i]\n    return (thin if octas >= 4 else clear)[i]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['wind 1.0 day strong 2 octas', [1.0, True, 'strong', 2], 'A'], ['wind 1.0 day moderate 5 octas', [1.0, True, 'moderate', 5], 'A-B'], ['wind 1.0 day slight 8 octas', [1.0, True, 'slight', 8], 'D'], ['wind 1.0 day slight 3 octas', [1.0, True, 'slight', 3], 'B'], ['wind 1.0 night None 3 octas', [1.0, False, None, 3], 'F'], ['wind 1.0 night None 4 octas', [1.0, False, None, 4], 'E'], ['wind 1.0 night None 8 octas', [1.0, False, None, 8], 'D'], ['wind 1.0 day strong 7 octas', [1.0, True, 'strong', 7], 'A']], [['wind 1.0 day overcast-ish 4 octas', [1.0, True, 'overcast-ish', 4], None], ['wind 1.0 night None 7 octas', [1.0, False, None, 7], 'E'], ['wind 1.0 day strong 7 octas', [1.0, True, 'strong', 7], 'A'], ['wind 1.9 day strong 2 octas', [1.9, True, 'strong', 2], 'A'], ['wind 1.9 day moderate 5 octas', [1.9, True, 'moderate', 5], 'A-B'], ['wind 1.9 day slight 8 octas', [1.9, True, 'slight', 8], 'D'], ['wind 2.9 day slight 8 octas', [2.9, True, 'slight', 8], 'D'], ['wind 2.9 night None 7 octas', [2.9, False, None, 7], 'E']], [['wind 1.0 day slight 8 octas', [1.0, True, 'slight', 8], 'D'], ['wind 1.9 night None 3 octas', [1.9, False, None, 3], 'F'], ['wind 1.9 night None 4 octas', [1.9, False, None, 4], 'E'], ['wind 1.9 night None 8 octas', [1.9, False, None, 8], 'D'], ['wind 1.9 day overcast-ish 4 octas', [1.9, True, 'overcast-ish', 4], None], ['wind 1.9 night None 7 octas', [1.9, False, None, 7], 'E'], ['wind 1.9 day strong 7 octas', [1.9, True, 'strong', 7], 'A'], ['wind 5.9 day strong 7 octas', [5.9, True, 'strong', 7], 'C']], [['wind 1.9 night None 7 octas', [1.9, False, None, 7], 'E'], ['wind 2.0 day moderate 5 octas', [2.0, True, 'moderate', 5], 'B'], ['wind 2.0 day slight 8 octas', [2.0, True, 'slight', 8], 'D'], ['wind 2.0 day slight 3 octas', [2.0, True, 'slight', 3], 'C'], ['wind 2.0 night None 3 octas', [2.0, False, None, 3], 'F'], ['wind 2.0 night None 4 octas', [2.0, False, None, 4], 'E'], ['wind 2.0 night None 8 octas', [2.0, False, None, 8], 'D'], ['wind 2.9 day slight 8 octas', [2.9, True, 'slight', 8], 'D']], [['wind 1.0 day slight 8 octas', [1.0, True, 'slight', 8], 'D'], ['wind 2.0 night None 7 octas', [2.0, False, None, 7], 'E'], ['wind 2.0 day strong 7 octas', [2.0, True, 'strong', 7], 'A-B'], ['wind 2.9 day strong 2 octas', [2.9, True, 'strong', 2], 'A-B'], ['wind 2.9 day moderate 5 octas', [2.9, True, 'moderate', 5], 'B'], ['wind 2.9 day slight 8 octas', [2.9, True, 'slight', 8], 'D'], ['wind 2.9 day slight 3 octas', [2.9, True, 'slight', 3], 'C'], ['wind 2.9 day strong 7 octas', [2.9, True, 'strong', 7], 'A-B']]]\nfor label, args, expected in fixtures[N - 1]:\n    check(label, solve(*args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":"Stipulated deterministic teaching model of an operational weather index; coefficients and thresholds are fixed by the contract and no claim of standards conformance is made. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"w2-weather_index_computation-pasquill-stability-overcast-neutral-override","generated_at":"2026-09-29T14:48:28.420588+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Air-dispersion screening models choose plume spread from the stability class.","root_cause":"The overcast neutral override is applied only at night.","sha256":"141b72124cfd2d17deff6da834fc3fdc45cdcd3239c408c03fd21cd4ee02bb59","title":"Pasquill-Gifford stability class: overcast neutral override · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":39.493,"exit_code":1,"observations":[{"actual":"A","check":"wind 1.0 day strong 2 octas","expected":"A","passed":true},{"actual":"A-B","check":"wind 1.0 day moderate 5 octas","expected":"A-B","passed":true},{"actual":"D","check":"wind 1.0 day slight 8 octas","expected":"D","passed":true},{"actual":"B","check":"wind 1.0 day slight 3 octas","expected":"B","passed":true},{"actual":"F","check":"wind 1.0 night None 3 octas","expected":"F","passed":true},{"actual":"E","check":"wind 1.0 night None 4 octas","expected":"E","passed":true},{"actual":"D","check":"wind 1.0 night None 8 octas","expected":"D","passed":true},{"actual":"D","check":"wind 1.0 day strong 7 octas","expected":"A","passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"wind 1.0 day strong 2 octas\", \"actual\": \"A\", \"expected\": \"A\", \"passed\": true}, {\"check\": \"wind 1.0 day moderate 5 octas\", \"actual\": \"A-B\", \"expected\": \"A-B\", \"passed\": true}, {\"check\": \"wind 1.0 day slight 8 octas\", \"actual\": \"D\", \"expected\": \"D\", \"passed\": true}, {\"check\": \"wind 1.0 day slight 3 octas\", \"actual\": \"B\", \"expected\": \"B\", \"passed\": true}, {\"check\": \"wind 1.0 night None 3 octas\", \"actual\": \"F\", \"expected\": \"F\", \"passed\": true}, {\"check\": \"wind 1.0 night None 4 octas\", \"actual\": \"E\", \"expected\": \"E\", \"passed\": true}, {\"check\": \"wind 1.0 night None 8 octas\", \"actual\": \"D\", \"expected\": \"D\", \"passed\": true}, {\"check\": \"wind 1.0 day strong 7 octas\", \"actual\": \"D\", \"expected\": \"A\", \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":39.817,"exit_code":1,"observations":[{"actual":"A","check":"wind 1.0 day strong 2 octas","expected":"A","passed":true},{"actual":"A-B","check":"wind 1.0 day moderate 5 octas","expected":"A-B","passed":true},{"actual":"B","check":"wind 1.0 day slight 8 octas","expected":"D","passed":false},{"actual":"B","check":"wind 1.0 day slight 3 octas","expected":"B","passed":true},{"actual":"F","check":"wind 1.0 night None 3 octas","expected":"F","passed":true},{"actual":"E","check":"wind 1.0 night None 4 octas","expected":"E","passed":true},{"actual":"D","check":"wind 1.0 night None 8 octas","expected":"D","passed":true},{"actual":"A","check":"wind 1.0 day strong 7 octas","expected":"A","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"wind 1.0 day strong 2 octas\", \"actual\": \"A\", \"expected\": \"A\", \"passed\": true}, {\"check\": \"wind 1.0 day moderate 5 octas\", \"actual\": \"A-B\", \"expected\": \"A-B\", \"passed\": true}, {\"check\": \"wind 1.0 day slight 8 octas\", \"actual\": \"B\", \"expected\": \"D\", \"passed\": false}, {\"check\": \"wind 1.0 day slight 3 octas\", \"actual\": \"B\", \"expected\": \"B\", \"passed\": true}, {\"check\": \"wind 1.0 night None 3 octas\", \"actual\": \"F\", \"expected\": \"F\", \"passed\": true}, {\"check\": \"wind 1.0 night None 4 octas\", \"actual\": \"E\", \"expected\": \"E\", \"passed\": true}, {\"check\": \"wind 1.0 night None 8 octas\", \"actual\": \"D\", \"expected\": \"D\", \"passed\": true}, {\"check\": \"wind 1.0 day strong 7 octas\", \"actual\": \"A\", \"expected\": \"A\", \"passed\": true}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}