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convert/windchill

convert temperature-speed pairs to windchill

 

Calling Sequence

Parameters

Options

Description

Examples

References

Calling Sequence

convert([t, s], windchill, [ut, us], opts)

convert([t*Unit(ut), s*Unit(us)], windchill, opts)

Parameters

t

-

temperature

s

-

wind speed

ut

-

units of temperature

us

-

units of wind speed

opts

-

equation options as described below

Options

• 

formula : one of OsczevskiBluestein or SiplePassel (see description); default is OsczevskiBluestein.

Description

• 

The convert([t, s], windchill, [ut, us]) function converts the temperature-speed pair t,s to the corresponding windchill factor corresponding to the units of temperature ut.

• 

The convert([t*Unit(ut), s*Unit(us)], windchill ) function is similar to the first calling sequence.

• 

The formula used by the U.S. National Weather Service and Environment Canada is

35.74+0.6215T35.75V0.16+0.4275TV0.16

  

where T is the temperature in degrees Fahrenheit, and V is the wind velocity in miles per hour.  The result is the apparent temperature in degrees Fahrenheit.

• 

The above formula was developed in 2001 by the Joint Action Group for Temperature Indices (see Osczevski and Bluestein).

• 

This calculation is intended as an approximation. It is used only for wind speeds between 4 mph ( 6kmh ) and 50 mph ( 80kmh ).

• 

The above Osczevski-Bluestein formula replaces an earlier formula for windchill due to Siple and Passel:

91.4+0.4746770.020425V+0.303107VT91.4

  

in which the variables are defined as in the previous formula.

  

Windchill computations using the Siple-Passel formula are possible by adding the option formula=SiplePassel in the call to convert.

Examples

Determine the apparent temperature with a temperature of 37°F and wind velocity of 10 mph.

convert37,10,windchill,degF,mph

29.92427177

(1)

Compare this result to the result using historical Siple-Passel formula for wind chill.

convert37,10,windchill,degF,mph,formula=SiplePassel

24.54590909

(2)

Determine the apparent temperature with a temperature of 3°C and wind velocity of 16 km/h.

convert3,16,windchill,degC,kmh

0.8629766

(3)

Convert the resulting temperature from Celsius to Fahrenheit.

convert,temperature,degC,degF

30.4466421

(4)

References

  

Osczevski, Randall, Maurice Bluestein, 2005: The New Wind Chill Equivalent Temperature Chart. Bulletin of the American Meteorological Society, 86, 1453–1458. doi: http://dx.doi.org/10.1175/BAMS-86-10-1453

See Also

convert

convert/temperature

evalf

Units

Units/Index

Units/Standard

Units/temperature

 


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