FA-70986 / Weather index computation / Open access

WBGT heat flag: flag from reported value · case 01

The posted WBGT and the flag colour disagree near a flag boundary (26.7 degC posted with a white flag).

Verified by executionVariant 1 · 8 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The flag is computed from the unrounded WBGT while the rounded value is posted.

VERIFIED REPAIR

Round WBGT to 0.1 degC first and derive the flag from that value.

Unsuccessful approach: Rounding the Fahrenheit value to a whole degree moves 84.9 degF into the yellow band.

Case contract

Inputs natural wet bulb, globe and dry bulb in degC and whether the site is in sun. Sun: WBGT = 0.7Tw + 0.2Tg + 0.1Td; shade/indoor: 0.7Tw + 0.3Tg; round to 0.1 degC. Convert the rounded value to degF (x*9/5+32) and flag: <80 white, <85 green, <88 yellow, <90 red, else black.

Why this case matters

Training and work/rest schedules follow the WBGT flag colour.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(tw, tg, td, solar):
    if solar:
        w = 0.7 * tw + 0.2 * tg + 0.1 * td
    else:
        w = 0.7 * tw + 0.3 * tg
    wf = w * 9 / 5 + 32
    w = round(w, 1)
    if wf < 80:
        flag = "white"
    elif wf < 85:
        flag = "green"
    elif wf < 88:
        flag = "yellow"
    elif wf < 90:
        flag = "red"
    else:
        flag = "black"
    return [w, flag]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['Tw 20 Tg 30 Td 25 sun', [20, 30, 25, True], [22.5, 'white']], ['Tw 20 Tg 30 Td 25 indoor', [20, 30, 25, False], [23.0, 'white']], ['Tw 24 Tg 35 Td 30 sun', [24, 35, 30, True], [26.8, 'green']], ['Tw 24 Tg 35 Td 30 indoor', [24, 35, 30, False], [27.3, 'green']], ['Tw 25 Tg 40 Td 31 sun', [25, 40, 31, True], [28.6, 'green']], ['Tw 25 Tg 40 Td 31 indoor', [25, 40, 31, False], [29.5, 'yellow']], ['Tw 28 Tg 45 Td 34 sun', [28, 45, 34, True], [32.0, 'red']], ['indoor raw 26.66', [20, 42.2, 30, False], [26.7, 'green']]], [['Tw 26 Tg 38 Td 30 indoor', [26, 38, 30, False], [29.6, 'yellow']], ['Tw 27 Tg 36 Td 32 sun', [27, 36, 32, True], [29.3, 'green']], ['Tw 27 Tg 36 Td 32 indoor', [27, 36, 32, False], [29.7, 'yellow']], ['Tw 28 Tg 45 Td 34 sun', [28, 45, 34, True], [32.0, 'red']], ['Tw 28 Tg 45 Td 34 indoor', [28, 45, 34, False], [33.1, 'black']], ['Tw 29 Tg 30 Td 29 sun', [29, 30, 29, True], [29.2, 'green']], ['Tw 29 Tg 30 Td 29 indoor', [29, 30, 29, False], [29.3, 'green']], ['indoor raw 26.66', [20, 42.2, 30, False], [26.7, 'green']]], [['Tw 30 Tg 50 Td 35 sun', [30, 50, 35, True], [34.5, 'black']], ['Tw 30 Tg 50 Td 35 indoor', [30, 50, 35, False], [36.0, 'black']], ['Tw 31 Tg 40 Td 33 sun', [31, 40, 33, True], [33.0, 'black']], ['Tw 31 Tg 40 Td 33 indoor', [31, 40, 33, False], [33.7, 'black']], ['Tw 22 Tg 26 Td 24 sun', [22, 26, 24, True], [23.0, 'white']], ['Tw 22 Tg 26 Td 24 indoor', [22, 26, 24, False], [23.2, 'white']], ['indoor raw 26.66', [20, 42.2, 30, False], [26.7, 'green']], ['field Tw 30.3 Tg 35.9 Td 35.9', [30.3, 35.9, 35.9, False], [32.0, 'red']]], [['Tw 27 Tg 29.4 Td 30 indoor', [27, 29.4, 30, False], [27.7, 'green']], ['Tw 26.4 Tg 30 Td 29 sun', [26.4, 30, 29, True], [27.4, 'green']], ['Tw 26.4 Tg 30 Td 29 indoor', [26.4, 30, 29, False], [27.5, 'green']], ['indoor raw 26.66', [20, 42.2, 30, False], [26.7, 'green']], ['indoor raw 29.43', [21, 49.1, 30, False], [29.4, 'green']], ['sun raw 26.66', [20, 41.3, 30.6, True], [25.3, 'white']], ['field Tw 22.5 Tg 25.2 Td 27.7', [22.5, 25.2, 27.7, True], [23.6, 'white']], ['field Tw 25.5 Tg 32.1 Td 26.0', [25.5, 32.1, 26.0, False], [27.5, 'green']]], [['Tw 29 Tg 30 Td 29 indoor', [29, 30, 29, False], [29.3, 'green']], ['indoor raw 26.66', [20, 42.2, 30, False], [26.7, 'green']], ['field Tw 25.5 Tg 32.1 Td 26.0', [25.5, 32.1, 26.0, False], [27.5, 'green']], ['field Tw 18.5 Tg 26.3 Td 19.1', [18.5, 26.3, 19.1, True], [20.1, 'white']], ['field Tw 23.9 Tg 38.8 Td 24.9', [23.9, 38.8, 24.9, True], [27.0, 'green']], ['field Tw 26.8 Tg 43.9 Td 31.4', [26.8, 43.9, 31.4, True], [30.7, 'yellow']], ['field Tw 31.7 Tg 32.5 Td 38.6', [31.7, 32.5, 38.6, True], [32.5, 'black']], ['field Tw 20.0 Tg 22.1 Td 22.5', [20.0, 22.1, 22.5, False], [20.6, 'white']]]]
for label, args, expected in fixtures[N - 1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
Tw 20 Tg 30 Td 25 sun	`[22.5, 'white']`	`[22.5, 'white']`	Passed
Tw 20 Tg 30 Td 25 indoor	`[23.0, 'white']`	`[23.0, 'white']`	Passed
Tw 24 Tg 35 Td 30 sun	`[26.8, 'green']`	`[26.8, 'green']`	Passed
Tw 24 Tg 35 Td 30 indoor	`[27.3, 'green']`	`[27.3, 'green']`	Passed
Tw 25 Tg 40 Td 31 sun	`[28.6, 'green']`	`[28.6, 'green']`	Passed
Tw 25 Tg 40 Td 31 indoor	`[29.5, 'yellow']`	`[29.5, 'yellow']`	Passed
Tw 28 Tg 45 Td 34 sun	`[32.0, 'red']`	`[32.0, 'red']`	Passed
indoor raw 26.66	`[26.7, 'white']`	`[26.7, 'green']`	Failed

SHA-256 / 25fa16a9112e54a8674e7a4fa7e1819c852b5bc5288c73c3c76f5e003d3f7c32

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(tw, tg, td, solar):
    if solar:
        w = 0.7 * tw + 0.2 * tg + 0.1 * td
    else:
        w = 0.7 * tw + 0.3 * tg
    w = round(w, 1)
    wf = round(w * 9 / 5 + 32)
    if wf < 80:
        flag = "white"
    elif wf < 85:
        flag = "green"
    elif wf < 88:
        flag = "yellow"
    elif wf < 90:
        flag = "red"
    else:
        flag = "black"
    return [w, flag]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['Tw 20 Tg 30 Td 25 sun', [20, 30, 25, True], [22.5, 'white']], ['Tw 20 Tg 30 Td 25 indoor', [20, 30, 25, False], [23.0, 'white']], ['Tw 24 Tg 35 Td 30 sun', [24, 35, 30, True], [26.8, 'green']], ['Tw 24 Tg 35 Td 30 indoor', [24, 35, 30, False], [27.3, 'green']], ['Tw 25 Tg 40 Td 31 sun', [25, 40, 31, True], [28.6, 'green']], ['Tw 25 Tg 40 Td 31 indoor', [25, 40, 31, False], [29.5, 'yellow']], ['Tw 28 Tg 45 Td 34 sun', [28, 45, 34, True], [32.0, 'red']], ['indoor raw 26.66', [20, 42.2, 30, False], [26.7, 'green']]], [['Tw 26 Tg 38 Td 30 indoor', [26, 38, 30, False], [29.6, 'yellow']], ['Tw 27 Tg 36 Td 32 sun', [27, 36, 32, True], [29.3, 'green']], ['Tw 27 Tg 36 Td 32 indoor', [27, 36, 32, False], [29.7, 'yellow']], ['Tw 28 Tg 45 Td 34 sun', [28, 45, 34, True], [32.0, 'red']], ['Tw 28 Tg 45 Td 34 indoor', [28, 45, 34, False], [33.1, 'black']], ['Tw 29 Tg 30 Td 29 sun', [29, 30, 29, True], [29.2, 'green']], ['Tw 29 Tg 30 Td 29 indoor', [29, 30, 29, False], [29.3, 'green']], ['indoor raw 26.66', [20, 42.2, 30, False], [26.7, 'green']]], [['Tw 30 Tg 50 Td 35 sun', [30, 50, 35, True], [34.5, 'black']], ['Tw 30 Tg 50 Td 35 indoor', [30, 50, 35, False], [36.0, 'black']], ['Tw 31 Tg 40 Td 33 sun', [31, 40, 33, True], [33.0, 'black']], ['Tw 31 Tg 40 Td 33 indoor', [31, 40, 33, False], [33.7, 'black']], ['Tw 22 Tg 26 Td 24 sun', [22, 26, 24, True], [23.0, 'white']], ['Tw 22 Tg 26 Td 24 indoor', [22, 26, 24, False], [23.2, 'white']], ['indoor raw 26.66', [20, 42.2, 30, False], [26.7, 'green']], ['field Tw 30.3 Tg 35.9 Td 35.9', [30.3, 35.9, 35.9, False], [32.0, 'red']]], [['Tw 27 Tg 29.4 Td 30 indoor', [27, 29.4, 30, False], [27.7, 'green']], ['Tw 26.4 Tg 30 Td 29 sun', [26.4, 30, 29, True], [27.4, 'green']], ['Tw 26.4 Tg 30 Td 29 indoor', [26.4, 30, 29, False], [27.5, 'green']], ['indoor raw 26.66', [20, 42.2, 30, False], [26.7, 'green']], ['indoor raw 29.43', [21, 49.1, 30, False], [29.4, 'green']], ['sun raw 26.66', [20, 41.3, 30.6, True], [25.3, 'white']], ['field Tw 22.5 Tg 25.2 Td 27.7', [22.5, 25.2, 27.7, True], [23.6, 'white']], ['field Tw 25.5 Tg 32.1 Td 26.0', [25.5, 32.1, 26.0, False], [27.5, 'green']]], [['Tw 29 Tg 30 Td 29 indoor', [29, 30, 29, False], [29.3, 'green']], ['indoor raw 26.66', [20, 42.2, 30, False], [26.7, 'green']], ['field Tw 25.5 Tg 32.1 Td 26.0', [25.5, 32.1, 26.0, False], [27.5, 'green']], ['field Tw 18.5 Tg 26.3 Td 19.1', [18.5, 26.3, 19.1, True], [20.1, 'white']], ['field Tw 23.9 Tg 38.8 Td 24.9', [23.9, 38.8, 24.9, True], [27.0, 'green']], ['field Tw 26.8 Tg 43.9 Td 31.4', [26.8, 43.9, 31.4, True], [30.7, 'yellow']], ['field Tw 31.7 Tg 32.5 Td 38.6', [31.7, 32.5, 38.6, True], [32.5, 'black']], ['field Tw 20.0 Tg 22.1 Td 22.5', [20.0, 22.1, 22.5, False], [20.6, 'white']]]]
for label, args, expected in fixtures[N - 1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
Tw 20 Tg 30 Td 25 sun	`[22.5, 'white']`	`[22.5, 'white']`	Passed
Tw 20 Tg 30 Td 25 indoor	`[23.0, 'white']`	`[23.0, 'white']`	Passed
Tw 24 Tg 35 Td 30 sun	`[26.8, 'green']`	`[26.8, 'green']`	Passed
Tw 24 Tg 35 Td 30 indoor	`[27.3, 'green']`	`[27.3, 'green']`	Passed
Tw 25 Tg 40 Td 31 sun	`[28.6, 'green']`	`[28.6, 'green']`	Passed
Tw 25 Tg 40 Td 31 indoor	`[29.5, 'yellow']`	`[29.5, 'yellow']`	Passed
Tw 28 Tg 45 Td 34 sun	`[32.0, 'black']`	`[32.0, 'red']`	Failed
indoor raw 26.66	`[26.7, 'green']`	`[26.7, 'green']`	Passed

SHA-256 / 08f2c929ede9b1e56335faeabd5e53c0f388574ae65dc5c8fa10ada21d65ce15

3 / The verified repair

Exit 0

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(tw, tg, td, solar):
    if solar:
        w = 0.7 * tw + 0.2 * tg + 0.1 * td
    else:
        w = 0.7 * tw + 0.3 * tg
    w = round(w, 1)
    wf = w * 9 / 5 + 32
    if wf < 80:
        flag = "white"
    elif wf < 85:
        flag = "green"
    elif wf < 88:
        flag = "yellow"
    elif wf < 90:
        flag = "red"
    else:
        flag = "black"
    return [w, flag]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['Tw 20 Tg 30 Td 25 sun', [20, 30, 25, True], [22.5, 'white']], ['Tw 20 Tg 30 Td 25 indoor', [20, 30, 25, False], [23.0, 'white']], ['Tw 24 Tg 35 Td 30 sun', [24, 35, 30, True], [26.8, 'green']], ['Tw 24 Tg 35 Td 30 indoor', [24, 35, 30, False], [27.3, 'green']], ['Tw 25 Tg 40 Td 31 sun', [25, 40, 31, True], [28.6, 'green']], ['Tw 25 Tg 40 Td 31 indoor', [25, 40, 31, False], [29.5, 'yellow']], ['Tw 28 Tg 45 Td 34 sun', [28, 45, 34, True], [32.0, 'red']], ['indoor raw 26.66', [20, 42.2, 30, False], [26.7, 'green']]], [['Tw 26 Tg 38 Td 30 indoor', [26, 38, 30, False], [29.6, 'yellow']], ['Tw 27 Tg 36 Td 32 sun', [27, 36, 32, True], [29.3, 'green']], ['Tw 27 Tg 36 Td 32 indoor', [27, 36, 32, False], [29.7, 'yellow']], ['Tw 28 Tg 45 Td 34 sun', [28, 45, 34, True], [32.0, 'red']], ['Tw 28 Tg 45 Td 34 indoor', [28, 45, 34, False], [33.1, 'black']], ['Tw 29 Tg 30 Td 29 sun', [29, 30, 29, True], [29.2, 'green']], ['Tw 29 Tg 30 Td 29 indoor', [29, 30, 29, False], [29.3, 'green']], ['indoor raw 26.66', [20, 42.2, 30, False], [26.7, 'green']]], [['Tw 30 Tg 50 Td 35 sun', [30, 50, 35, True], [34.5, 'black']], ['Tw 30 Tg 50 Td 35 indoor', [30, 50, 35, False], [36.0, 'black']], ['Tw 31 Tg 40 Td 33 sun', [31, 40, 33, True], [33.0, 'black']], ['Tw 31 Tg 40 Td 33 indoor', [31, 40, 33, False], [33.7, 'black']], ['Tw 22 Tg 26 Td 24 sun', [22, 26, 24, True], [23.0, 'white']], ['Tw 22 Tg 26 Td 24 indoor', [22, 26, 24, False], [23.2, 'white']], ['indoor raw 26.66', [20, 42.2, 30, False], [26.7, 'green']], ['field Tw 30.3 Tg 35.9 Td 35.9', [30.3, 35.9, 35.9, False], [32.0, 'red']]], [['Tw 27 Tg 29.4 Td 30 indoor', [27, 29.4, 30, False], [27.7, 'green']], ['Tw 26.4 Tg 30 Td 29 sun', [26.4, 30, 29, True], [27.4, 'green']], ['Tw 26.4 Tg 30 Td 29 indoor', [26.4, 30, 29, False], [27.5, 'green']], ['indoor raw 26.66', [20, 42.2, 30, False], [26.7, 'green']], ['indoor raw 29.43', [21, 49.1, 30, False], [29.4, 'green']], ['sun raw 26.66', [20, 41.3, 30.6, True], [25.3, 'white']], ['field Tw 22.5 Tg 25.2 Td 27.7', [22.5, 25.2, 27.7, True], [23.6, 'white']], ['field Tw 25.5 Tg 32.1 Td 26.0', [25.5, 32.1, 26.0, False], [27.5, 'green']]], [['Tw 29 Tg 30 Td 29 indoor', [29, 30, 29, False], [29.3, 'green']], ['indoor raw 26.66', [20, 42.2, 30, False], [26.7, 'green']], ['field Tw 25.5 Tg 32.1 Td 26.0', [25.5, 32.1, 26.0, False], [27.5, 'green']], ['field Tw 18.5 Tg 26.3 Td 19.1', [18.5, 26.3, 19.1, True], [20.1, 'white']], ['field Tw 23.9 Tg 38.8 Td 24.9', [23.9, 38.8, 24.9, True], [27.0, 'green']], ['field Tw 26.8 Tg 43.9 Td 31.4', [26.8, 43.9, 31.4, True], [30.7, 'yellow']], ['field Tw 31.7 Tg 32.5 Td 38.6', [31.7, 32.5, 38.6, True], [32.5, 'black']], ['field Tw 20.0 Tg 22.1 Td 22.5', [20.0, 22.1, 22.5, False], [20.6, 'white']]]]
for label, args, expected in fixtures[N - 1]:
    check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
Tw 20 Tg 30 Td 25 sun	`[22.5, 'white']`	`[22.5, 'white']`	Passed
Tw 20 Tg 30 Td 25 indoor	`[23.0, 'white']`	`[23.0, 'white']`	Passed
Tw 24 Tg 35 Td 30 sun	`[26.8, 'green']`	`[26.8, 'green']`	Passed
Tw 24 Tg 35 Td 30 indoor	`[27.3, 'green']`	`[27.3, 'green']`	Passed
Tw 25 Tg 40 Td 31 sun	`[28.6, 'green']`	`[28.6, 'green']`	Passed
Tw 25 Tg 40 Td 31 indoor	`[29.5, 'yellow']`	`[29.5, 'yellow']`	Passed
Tw 28 Tg 45 Td 34 sun	`[32.0, 'red']`	`[32.0, 'red']`	Passed
indoor raw 26.66	`[26.7, 'green']`	`[26.7, 'green']`	Passed

SHA-256 / 1c326735c7b7d1e0f62c047642a9cc748d3f5f4834dd8216c4f13319e90f179e

Verification & scope

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.

Observations recorded using Python 3.12.14 at 2026-09-29T14:48:25.601514+00:00.

Case digest / 509983e0208c6d9d3548d0f9cee81204c5db5e53e21c39f0d2797248f9313926