Cold Front Passing Temp Drop Rate

Audit observed interval cooling rates over irregular hours while preserving warming sign; temperature change alone does not establish a cold-front passage or weather hazard.

Description

Observed cooling rate depends on elapsed time, especially with irregular samples.

Observed cooling rate depends on elapsed time, especially with irregular samples. A signed cooling convention also records warming as negative cooling.^[1]

Audit observed interval cooling rates over irregular hours while preserving warming sign; temperature change alone does not establish a cold-front passage or weather hazard.

When to use Cold Front Passing Temp Drop Rate

Use this tool to audit observed interval cooling rates over irregular hours while preserving warming sign; temperature change alone does not establish a cold-front passage or weather hazard.

Prepare the observed sounding, cloud records or forecast verification data. Check pressure and height coordinates, wind conventions and the stated units.

How to use Cold Front Passing Temp Drop Rate and understand its results

Prepare the observed sounding, cloud records or forecast verification data. Check pressure and height coordinates, wind conventions and the stated units.
Enter observationHours, observedTemperaturesC using the field table and calculation rules, then run the tool.
Read intervalSignedCoolingRatesCPerHour, maximumObservedCoolingRateCPerHour, netCoolingC. 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
observationHours	Observation hours	list of number	Required
observedTemperaturesC	Observed temperatures c	list of number	Required

Pair Celsius temperatures with at least two increasing observation hours. Return adjacent signed rates in °C/hour, the largest signed cooling rate and first-minus-last net cooling. Entirely warming data can have a negative maximum cooling rate.

Paired lists must be nonempty and have equal lengths. Each sequence checked for increasing order must contain at least two strictly increasing values.

cooling rate = (earlier temperature − later temperature)/elapsed hours

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

Output field	Meaning	Value type
intervalSignedCoolingRatesCPerHour	Interval signed cooling rates c per hour	list of number
maximumObservedCoolingRateCPerHour	Maximum observed cooling rate c per hour	number
netCoolingC	Net cooling c	number

json

{
  "input": {
    "observationHours": [
      0,
      1,
      3
    ],
    "observedTemperaturesC": [
      20,
      15,
      13
    ]
  },
  "output": {
    "intervalSignedCoolingRatesCPerHour": [
      5,
      1
    ],
    "maximumObservedCoolingRateCPerHour": 5,
    "netCoolingC": 7
  }
}

Limitations and assumptions

Temperature changes alone do not establish frontal passage or a weather hazard.

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 Pressure Tendency 3HR Change: Calculate signed observed three-hour pressure tendency with bracketed piecewise-linear samples at report time; no unobserved extrapolation or synoptic symbol/weather inference. For a complementary task, use Dryline Mixing Ratio Gradient Checker: Screen observed signed moisture gradients on caller measured planar transect distances; no coordinate distance computation or dryline identification from humidity gradient alone.

References

Cold Front Passing Temp Drop Rate — tool.io

Similar or alternative tools

Pressure Tendency 3HR Change
Calculate signed observed three-hour pressure tendency with bracketed piecewise-linear samples at report time; no unobserved extrapolation or synoptic symbol/weather inference.
Dryline Mixing Ratio Gradient Checker
Screen observed signed moisture gradients on caller measured planar transect distances; no coordinate distance computation or dryline identification from humidity gradient alone.