Cloud Base Height from Spread (quick field rule) implementation

Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

Record owner

Guth Instruments

Lifecycle

verified-clean

Evidence ID

t5-170

Effect

Computation or source lookup only

Input and validation requirements

The formula produces a negative raw height when dew point exceeds temperature and overflows to Infinity for opposite extreme finite inputs. Both cases should be rejected or explicitly flagged rather than silently returned as ordinary estimates.

Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

{
  "inputs": {
    "temperature_f": 70,
    "dew_point_f": 60
  },
  "expected_outputs": {
    "estimated_cloud_base_ft_agl": 4000
  },
  "working": "Spread = T − Td = 70 − 60 = 10 °F. Height ≈ 400 × 10 = 4,000 ft AGL."
}

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche5/tranche5-results.json