{"abstract":"Stronger wind makes it feel warmer.","category":"Weather index computation","checks":8,"contract":"Input air temperature degC, RH percent, wind in km/h measured at 10 m. e = RH/100*6.105*exp(17.27*Ta/(237.7+Ta)) hPa; wind in m/s = km/h / 3.6; AT = Ta + 0.33e - 0.70ws - 4.00 rounded to 0.1.","evaluation_group":"w2-weather_index_computation-apparent-temperature","failed_approach":"Restoring the sign but using 0.07 removes most of the wind cooling.","family":"w2-weather_index_computation-apparent-temperature-wind-cooling-sign","id":"FA-70946","implementations":{"attempt":{"sha256":"c230e8f821cb49e6921d958716f47db47d88bcff49a4265b232a9ef17f482e3f","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(ta, rh, wind_kmh):\n    e = rh / 100.0 * 6.105 * math.exp(17.27 * ta / (237.7 + ta))\n    ws = wind_kmh / 3.6\n    at = ta + 0.33 * e - 0.07 * ws - 4.00\n    return round(at, 1)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['-5 C 10% RH wind 0 km/h', [-5, 10, 0], -8.9], ['-5 C 10% RH wind 10 km/h', [-5, 10, 10], -10.8], ['-5 C 10% RH wind 36 km/h', [-5, 10, 36], -15.9], ['-5 C 10% RH wind 72 km/h', [-5, 10, 72], -22.9], ['-5 C 50% RH wind 0 km/h', [-5, 50, 0], -8.3], ['-5 C 50% RH wind 10 km/h', [-5, 50, 10], -10.2], ['-5 C 50% RH wind 36 km/h', [-5, 50, 36], -15.3], ['-5 C 50% RH wind 72 km/h', [-5, 50, 72], -22.3]], [['-5 C 50% RH wind 10 km/h', [-5, 50, 10], -10.2], ['-5 C 50% RH wind 72 km/h', [-5, 50, 72], -22.3], ['-5 C 90% RH wind 0 km/h', [-5, 90, 0], -7.7], ['-5 C 90% RH wind 10 km/h', [-5, 90, 10], -9.7], ['-5 C 90% RH wind 36 km/h', [-5, 90, 36], -14.7], ['-5 C 90% RH wind 72 km/h', [-5, 90, 72], -21.7], ['0 C 10% RH wind 0 km/h', [0, 10, 0], -3.8], ['0 C 10% RH wind 10 km/h', [0, 10, 10], -5.7]], [['-5 C 90% RH wind 10 km/h', [-5, 90, 10], -9.7], ['0 C 10% RH wind 36 km/h', [0, 10, 36], -10.8], ['0 C 10% RH wind 72 km/h', [0, 10, 72], -17.8], ['0 C 50% RH wind 0 km/h', [0, 50, 0], -3.0], ['0 C 50% RH wind 10 km/h', [0, 50, 10], -4.9], ['0 C 50% RH wind 36 km/h', [0, 50, 36], -10.0], ['0 C 50% RH wind 72 km/h', [0, 50, 72], -17.0], ['0 C 90% RH wind 0 km/h', [0, 90, 0], -2.2]], [['0 C 10% RH wind 10 km/h', [0, 10, 10], -5.7], ['0 C 90% RH wind 10 km/h', [0, 90, 10], -4.1], ['0 C 90% RH wind 36 km/h', [0, 90, 36], -9.2], ['0 C 90% RH wind 72 km/h', [0, 90, 72], -16.2], ['12 C 10% RH wind 0 km/h', [12, 10, 0], 8.5], ['12 C 10% RH wind 10 km/h', [12, 10, 10], 6.5], ['12 C 10% RH wind 36 km/h', [12, 10, 36], 1.5], ['12 C 10% RH wind 72 km/h', [12, 10, 72], -5.5]], [['0 C 50% RH wind 10 km/h', [0, 50, 10], -4.9], ['12 C 50% RH wind 0 km/h', [12, 50, 0], 10.3], ['12 C 50% RH wind 10 km/h', [12, 50, 10], 8.4], ['12 C 50% RH wind 36 km/h', [12, 50, 36], 3.3], ['12 C 50% RH wind 72 km/h', [12, 50, 72], -3.7], ['12 C 90% RH wind 0 km/h', [12, 90, 0], 12.2], ['12 C 90% RH wind 10 km/h', [12, 90, 10], 10.2], ['12 C 90% RH wind 36 km/h', [12, 90, 36], 5.2]]]\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":"79edee94ef4cc6670293a38aebf3ca05c5e202b4143899f37bdb4f195169f426","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(ta, rh, wind_kmh):\n    e = rh / 100.0 * 6.105 * math.exp(17.27 * ta / (237.7 + ta))\n    ws = wind_kmh / 3.6\n    at = ta + 0.33 * e + 0.70 * ws - 4.00\n    return round(at, 1)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['-5 C 10% RH wind 0 km/h', [-5, 10, 0], -8.9], ['-5 C 10% RH wind 10 km/h', [-5, 10, 10], -10.8], ['-5 C 10% RH wind 36 km/h', [-5, 10, 36], -15.9], ['-5 C 10% RH wind 72 km/h', [-5, 10, 72], -22.9], ['-5 C 50% RH wind 0 km/h', [-5, 50, 0], -8.3], ['-5 C 50% RH wind 10 km/h', [-5, 50, 10], -10.2], ['-5 C 50% RH wind 36 km/h', [-5, 50, 36], -15.3], ['-5 C 50% RH wind 72 km/h', [-5, 50, 72], -22.3]], [['-5 C 50% RH wind 10 km/h', [-5, 50, 10], -10.2], ['-5 C 50% RH wind 72 km/h', [-5, 50, 72], -22.3], ['-5 C 90% RH wind 0 km/h', [-5, 90, 0], -7.7], ['-5 C 90% RH wind 10 km/h', [-5, 90, 10], -9.7], ['-5 C 90% RH wind 36 km/h', [-5, 90, 36], -14.7], ['-5 C 90% RH wind 72 km/h', [-5, 90, 72], -21.7], ['0 C 10% RH wind 0 km/h', [0, 10, 0], -3.8], ['0 C 10% RH wind 10 km/h', [0, 10, 10], -5.7]], [['-5 C 90% RH wind 10 km/h', [-5, 90, 10], -9.7], ['0 C 10% RH wind 36 km/h', [0, 10, 36], -10.8], ['0 C 10% RH wind 72 km/h', [0, 10, 72], -17.8], ['0 C 50% RH wind 0 km/h', [0, 50, 0], -3.0], ['0 C 50% RH wind 10 km/h', [0, 50, 10], -4.9], ['0 C 50% RH wind 36 km/h', [0, 50, 36], -10.0], ['0 C 50% RH wind 72 km/h', [0, 50, 72], -17.0], ['0 C 90% RH wind 0 km/h', [0, 90, 0], -2.2]], [['0 C 10% RH wind 10 km/h', [0, 10, 10], -5.7], ['0 C 90% RH wind 10 km/h', [0, 90, 10], -4.1], ['0 C 90% RH wind 36 km/h', [0, 90, 36], -9.2], ['0 C 90% RH wind 72 km/h', [0, 90, 72], -16.2], ['12 C 10% RH wind 0 km/h', [12, 10, 0], 8.5], ['12 C 10% RH wind 10 km/h', [12, 10, 10], 6.5], ['12 C 10% RH wind 36 km/h', [12, 10, 36], 1.5], ['12 C 10% RH wind 72 km/h', [12, 10, 72], -5.5]], [['0 C 50% RH wind 10 km/h', [0, 50, 10], -4.9], ['12 C 50% RH wind 0 km/h', [12, 50, 0], 10.3], ['12 C 50% RH wind 10 km/h', [12, 50, 10], 8.4], ['12 C 50% RH wind 36 km/h', [12, 50, 36], 3.3], ['12 C 50% RH wind 72 km/h', [12, 50, 72], -3.7], ['12 C 90% RH wind 0 km/h', [12, 90, 0], 12.2], ['12 C 90% RH wind 10 km/h', [12, 90, 10], 10.2], ['12 C 90% RH wind 36 km/h', [12, 90, 36], 5.2]]]\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"},"fixed":{"sha256":"2c5326c695f0a4664a65b5a92f56ba4ee02630b275fd0ca145c11a792a09feb5","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(ta, rh, wind_kmh):\n    e = rh / 100.0 * 6.105 * math.exp(17.27 * ta / (237.7 + ta))\n    ws = wind_kmh / 3.6\n    at = ta + 0.33 * e - 0.70 * ws - 4.00\n    return round(at, 1)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['-5 C 10% RH wind 0 km/h', [-5, 10, 0], -8.9], ['-5 C 10% RH wind 10 km/h', [-5, 10, 10], -10.8], ['-5 C 10% RH wind 36 km/h', [-5, 10, 36], -15.9], ['-5 C 10% RH wind 72 km/h', [-5, 10, 72], -22.9], ['-5 C 50% RH wind 0 km/h', [-5, 50, 0], -8.3], ['-5 C 50% RH wind 10 km/h', [-5, 50, 10], -10.2], ['-5 C 50% RH wind 36 km/h', [-5, 50, 36], -15.3], ['-5 C 50% RH wind 72 km/h', [-5, 50, 72], -22.3]], [['-5 C 50% RH wind 10 km/h', [-5, 50, 10], -10.2], ['-5 C 50% RH wind 72 km/h', [-5, 50, 72], -22.3], ['-5 C 90% RH wind 0 km/h', [-5, 90, 0], -7.7], ['-5 C 90% RH wind 10 km/h', [-5, 90, 10], -9.7], ['-5 C 90% RH wind 36 km/h', [-5, 90, 36], -14.7], ['-5 C 90% RH wind 72 km/h', [-5, 90, 72], -21.7], ['0 C 10% RH wind 0 km/h', [0, 10, 0], -3.8], ['0 C 10% RH wind 10 km/h', [0, 10, 10], -5.7]], [['-5 C 90% RH wind 10 km/h', [-5, 90, 10], -9.7], ['0 C 10% RH wind 36 km/h', [0, 10, 36], -10.8], ['0 C 10% RH wind 72 km/h', [0, 10, 72], -17.8], ['0 C 50% RH wind 0 km/h', [0, 50, 0], -3.0], ['0 C 50% RH wind 10 km/h', [0, 50, 10], -4.9], ['0 C 50% RH wind 36 km/h', [0, 50, 36], -10.0], ['0 C 50% RH wind 72 km/h', [0, 50, 72], -17.0], ['0 C 90% RH wind 0 km/h', [0, 90, 0], -2.2]], [['0 C 10% RH wind 10 km/h', [0, 10, 10], -5.7], ['0 C 90% RH wind 10 km/h', [0, 90, 10], -4.1], ['0 C 90% RH wind 36 km/h', [0, 90, 36], -9.2], ['0 C 90% RH wind 72 km/h', [0, 90, 72], -16.2], ['12 C 10% RH wind 0 km/h', [12, 10, 0], 8.5], ['12 C 10% RH wind 10 km/h', [12, 10, 10], 6.5], ['12 C 10% RH wind 36 km/h', [12, 10, 36], 1.5], ['12 C 10% RH wind 72 km/h', [12, 10, 72], -5.5]], [['0 C 50% RH wind 10 km/h', [0, 50, 10], -4.9], ['12 C 50% RH wind 0 km/h', [12, 50, 0], 10.3], ['12 C 50% RH wind 10 km/h', [12, 50, 10], 8.4], ['12 C 50% RH wind 36 km/h', [12, 50, 36], 3.3], ['12 C 50% RH wind 72 km/h', [12, 50, 72], -3.7], ['12 C 90% RH wind 0 km/h', [12, 90, 0], 12.2], ['12 C 90% RH wind 10 km/h', [12, 90, 10], 10.2], ['12 C 90% RH wind 36 km/h', [12, 90, 36], 5.2]]]\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-apparent-temperature-wind-cooling-sign","generated_at":"2026-09-29T14:48:25.360598+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Feels-like temperature on consumer forecasts uses this non-radiative apparent temperature.","repair":"Subtract 0.70 times wind speed in m/s.","root_cause":"The wind term is added rather than subtracted.","sha256":"23bf7057befce9211e758957bd734166c1209184c3194cb6909b92d1bb88dbca","title":"Shade apparent temperature: wind cooling sign · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":37.514,"exit_code":1,"observations":[{"actual":-8.9,"check":"-5 C 10% RH wind 0 km/h","expected":-8.9,"passed":true},{"actual":-9.1,"check":"-5 C 10% RH wind 10 km/h","expected":-10.8,"passed":false},{"actual":-9.6,"check":"-5 C 10% RH wind 36 km/h","expected":-15.9,"passed":false},{"actual":-10.3,"check":"-5 C 10% RH wind 72 km/h","expected":-22.9,"passed":false},{"actual":-8.3,"check":"-5 C 50% RH wind 0 km/h","expected":-8.3,"passed":true},{"actual":-8.5,"check":"-5 C 50% RH wind 10 km/h","expected":-10.2,"passed":false},{"actual":-9.0,"check":"-5 C 50% RH wind 36 km/h","expected":-15.3,"passed":false},{"actual":-9.7,"check":"-5 C 50% RH wind 72 km/h","expected":-22.3,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"-5 C 10% RH wind 0 km/h\", \"actual\": -8.9, \"expected\": -8.9, \"passed\": true}, {\"check\": \"-5 C 10% RH wind 10 km/h\", \"actual\": -9.1, \"expected\": -10.8, \"passed\": false}, {\"check\": \"-5 C 10% RH wind 36 km/h\", \"actual\": -9.6, \"expected\": -15.9, \"passed\": false}, {\"check\": \"-5 C 10% RH wind 72 km/h\", \"actual\": -10.3, \"expected\": -22.9, \"passed\": false}, {\"check\": \"-5 C 50% RH wind 0 km/h\", \"actual\": -8.3, \"expected\": -8.3, \"passed\": true}, {\"check\": \"-5 C 50% RH wind 10 km/h\", \"actual\": -8.5, \"expected\": -10.2, \"passed\": false}, {\"check\": \"-5 C 50% RH wind 36 km/h\", \"actual\": -9.0, \"expected\": -15.3, \"passed\": false}, {\"check\": \"-5 C 50% RH wind 72 km/h\", \"actual\": -9.7, \"expected\": -22.3, \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":38.972,"exit_code":1,"observations":[{"actual":-8.9,"check":"-5 C 10% RH wind 0 km/h","expected":-8.9,"passed":true},{"actual":-6.9,"check":"-5 C 10% RH wind 10 km/h","expected":-10.8,"passed":false},{"actual":-1.9,"check":"-5 C 10% RH wind 36 km/h","expected":-15.9,"passed":false},{"actual":5.1,"check":"-5 C 10% RH wind 72 km/h","expected":-22.9,"passed":false},{"actual":-8.3,"check":"-5 C 50% RH wind 0 km/h","expected":-8.3,"passed":true},{"actual":-6.4,"check":"-5 C 50% RH wind 10 km/h","expected":-10.2,"passed":false},{"actual":-1.3,"check":"-5 C 50% RH wind 36 km/h","expected":-15.3,"passed":false},{"actual":5.7,"check":"-5 C 50% RH wind 72 km/h","expected":-22.3,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"-5 C 10% RH wind 0 km/h\", \"actual\": -8.9, \"expected\": -8.9, \"passed\": true}, {\"check\": \"-5 C 10% RH wind 10 km/h\", \"actual\": -6.9, \"expected\": -10.8, \"passed\": false}, {\"check\": \"-5 C 10% RH wind 36 km/h\", \"actual\": -1.9, \"expected\": -15.9, \"passed\": false}, {\"check\": \"-5 C 10% RH wind 72 km/h\", \"actual\": 5.1, \"expected\": -22.9, \"passed\": false}, {\"check\": \"-5 C 50% RH wind 0 km/h\", \"actual\": -8.3, \"expected\": -8.3, \"passed\": true}, {\"check\": \"-5 C 50% RH wind 10 km/h\", \"actual\": -6.4, \"expected\": -10.2, \"passed\": false}, {\"check\": \"-5 C 50% RH wind 36 km/h\", \"actual\": -1.3, \"expected\": -15.3, \"passed\": false}, {\"check\": \"-5 C 50% RH wind 72 km/h\", \"actual\": 5.7, \"expected\": -22.3, \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":38.671,"exit_code":0,"observations":[{"actual":-8.9,"check":"-5 C 10% RH wind 0 km/h","expected":-8.9,"passed":true},{"actual":-10.8,"check":"-5 C 10% RH wind 10 km/h","expected":-10.8,"passed":true},{"actual":-15.9,"check":"-5 C 10% RH wind 36 km/h","expected":-15.9,"passed":true},{"actual":-22.9,"check":"-5 C 10% RH wind 72 km/h","expected":-22.9,"passed":true},{"actual":-8.3,"check":"-5 C 50% RH wind 0 km/h","expected":-8.3,"passed":true},{"actual":-10.2,"check":"-5 C 50% RH wind 10 km/h","expected":-10.2,"passed":true},{"actual":-15.3,"check":"-5 C 50% RH wind 36 km/h","expected":-15.3,"passed":true},{"actual":-22.3,"check":"-5 C 50% RH wind 72 km/h","expected":-22.3,"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"-5 C 10% RH wind 0 km/h\", \"actual\": -8.9, \"expected\": -8.9, \"passed\": true}, {\"check\": \"-5 C 10% RH wind 10 km/h\", \"actual\": -10.8, \"expected\": -10.8, \"passed\": true}, {\"check\": \"-5 C 10% RH wind 36 km/h\", \"actual\": -15.9, \"expected\": -15.9, \"passed\": true}, {\"check\": \"-5 C 10% RH wind 72 km/h\", \"actual\": -22.9, \"expected\": -22.9, \"passed\": true}, {\"check\": \"-5 C 50% RH wind 0 km/h\", \"actual\": -8.3, \"expected\": -8.3, \"passed\": true}, {\"check\": \"-5 C 50% RH wind 10 km/h\", \"actual\": -10.2, \"expected\": -10.2, \"passed\": true}, {\"check\": \"-5 C 50% RH wind 36 km/h\", \"actual\": -15.3, \"expected\": -15.3, \"passed\": true}, {\"check\": \"-5 C 50% RH wind 72 km/h\", \"actual\": -22.3, \"expected\": -22.3, \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}