Description
Return normalized supplied direction only above a calm threshold.
Atmospheric vectors and coordinates use explicit reference directions, height datums and missing/calm conventions. A meteorological from-bearing differs from a velocity-to direction; a normalized label or corrected coordinate does not constitute an actual observation or a forecast.
Return normalized supplied direction only above a calm threshold.
When to use this tool
Use Wind Direction Calm Undefined Token when checking the stated wind-direction, vector or vertical-reference convention.
How to use the tool and how it works
- Enter speed, calmThreshold, suppliedDirection. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read directionDefined, direction. Inspect directionDefined before interpreting the associated values.
Return normalized supplied direction only above a calm threshold. Require speed/calmThreshold >= 0; directionDefined uses strict speed > threshold, direction wraps to [0,360) or is zero placeholder when undefined.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| speed | Speed | Required. Finite number; minimum 0. |
| calmThreshold | Calm Threshold | Required. Finite number; minimum 0. |
| suppliedDirection | Supplied Direction | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| directionDefined | Direction Defined | Required. Boolean. |
| direction | Wrapped degrees only when directionDefined; zero otherwise is a placeholder. | Required. Finite number. |
{
"input": {
"speed": 0,
"calmThreshold": 0.2,
"suppliedDirection": 270
},
"output": {
"directionDefined": false,
"direction": 0
}
}Limitations and assumptions
- An undefined zero is not a north wind; the calm threshold is supplied and no actual wind is measured.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use verified observations and documented station/vector conventions with an appropriate complete meteorological analysis for actual weather or operational decisions.
References
Similar or alternative tools
- Wind Component Calm Flag
Return vector wind speed and a supplied calm-policy flag.
- Atmospheric Science: Wind Vector Meteorological Sign
Return wind velocity components from a meteorological from-bearing.