Snow Weight - Area (rectangle)

Not Reviewed
Equation / Last modified by KurtHeckman on 2016/12/13 14:11
`"weight" = `
Snow Weight - Area (rectangle)
Variable Instructions Datatype
`(l)"rectangle length"` Length of the rectangular area covered in snow Decimal (m)
`(w)"rectangle width"` Width of the rectangular area covered in snow Decimal (m)
Snow depth Enter snow depth Decimal (m)
Snow Type Select the snow type Text
4 variables
KurtHeckman.Snow Weight - Area (rectangle)

This equation provides the approximate weight of snow on an rectangular area (e.g. roof).  The inputs are the dimensions of the rectangle covered (length times width), the depth of the snow, and the type of snow (based on standard snow types).  The result is in Kg, but can be converted via the pull-down menu.



Snow Water Equivalent (SWE) is the product of snow depth and snow density. It can be presented in units of either kg/m2 or m:

SWE (`(kg)/(m^2)`) = snow depth (m) x snow density (`(kg)/(m^3)`)
 SWE (m) = snow depth (m) x snow density (`(kg)/(m^3)`) / water density (`(kg)/(m^3)`)


You can calculate snow depth from SWE if you know the density of the snow.  Od course, density of snow can range anywhere from 5% when ambient air temperature is 14 F, and can range up to 20% if the temperature is 32 F.

The snow density will increase after the snowfall due to gravitational settling, packing, wind effects, melting and refreezing.

Type of snow or icedensities (kg/m³)
New snow (immediately after falling in calm)50-70
Damp new snow100-200
Settled snow200-300
Depth hoar100-300
Wind packed snow350-400
Firn   (granular snow)400-830
Very wet snow and firn700-800
Glacier ice830-917

The equation will use a median value for the ranges in the density value column.