Midflame Effective Wind Speed Adjuster

Transform reference wind observations with caller shelter/exposure factors and duration weights; no inferred canopy wind model or automatic wind/slope-equivalent spread input.

Description

Wind adjustment can account for supplied shelter or exposure at flame height.

Wind adjustment can account for supplied shelter or exposure at flame height. Time weighting describes the observed period without inferring a canopy-flow model.^[1]

Transform reference wind observations with caller shelter/exposure factors and duration weights; no inferred canopy wind model or automatic wind/slope-equivalent spread input.

When to use Midflame Effective Wind Speed Adjuster

Use this tool to transform reference wind observations with caller shelter/exposure factors and duration weights; no inferred canopy wind model or automatic wind/slope-equivalent spread input.

Gather the tree inventory, plot measurements or model parameters. Check diameter, area, time and moisture conventions; keep paired observations aligned.

How to use Midflame Effective Wind Speed Adjuster and understand its results

Gather the tree inventory, plot measurements or model parameters. Check diameter, area, time and moisture conventions; keep paired observations aligned.
Enter referenceWindSpeedsMPerSecond, windAdjustmentFactors, durationWeightsSeconds using the field table and calculation rules, then run the tool.
Read midflameWindSpeedsMPerSecond, durationWeightedMidflameWindMPerSecond. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
referenceWindSpeedsMPerSecond	Reference wind speeds m per second	list of number	Required
windAdjustmentFactors	Wind adjustment factors	list of number	Required
durationWeightsSeconds	Duration weights seconds	list of number	Required

Pair nonnegative reference m/s, factors in [0,1] and nonnegative duration weights with positive total duration. Return adjusted speeds and the duration-weighted mean.

Paired lists must be nonempty and have equal lengths.

midflame wind=reference wind × adjustment fraction; mean=Σwind × duration/Σduration

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
midflameWindSpeedsMPerSecond	Midflame wind speeds m per second	list of number
durationWeightedMidflameWindMPerSecond	Duration weighted midflame wind m per second	number

json

{
  "input": {
    "referenceWindSpeedsMPerSecond": [
      2,
      4
    ],
    "windAdjustmentFactors": [
      0.5,
      0.25
    ],
    "durationWeightsSeconds": [
      1,
      3
    ]
  },
  "output": {
    "midflameWindSpeedsMPerSecond": [
      1,
      1
    ],
    "durationWeightedMidflameWindMPerSecond": 1
  }
}

Limitations and assumptions

Factors are caller-calibrated. No slope-equivalent spread input or operational fire forecast is computed.

Numeric inputs and returned numeric values must be finite; an unrepresentable returned value produces an error. Numeric lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use Byram Fireline Intensity kW/m: Compute Byram heat-yield×consumed-fuel×front-spread fireline intensity using supplied dry fuel consumption, not full fuel load or a fire-danger/response recommendation. For a complementary task, use Cup Anemometer Calibration Constant: Calibrate measured cup rotation rates to reference wind with explicit intercept/slope and extrapolation flag; not a universal instrument constant, gust response or certified sensor accuracy.

References

Midflame Effective Wind Speed Adjuster — tool.io

Similar or alternative tools

Byram Fireline Intensity kW/m
Compute Byram heat-yield×consumed-fuel×front-spread fireline intensity using supplied dry fuel consumption, not full fuel load or a fire-danger/response recommendation.
Cup Anemometer Calibration Constant
Calibrate measured cup rotation rates to reference wind with explicit intercept/slope and extrapolation flag; not a universal instrument constant, gust response or certified sensor accuracy.