# Snow Weight - Area (rectangle)

Not Reviewed
"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
Type
Equation
Category
vCommons
Contents
4 variables
Rating
ID
KurtHeckman.Snow Weight - Area (rectangle)
UUID
ce0fc104-aafb-11e3-9cd9-bc764e2038f2

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.

# Notes

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 ice densities (kg/m³) New snow (immediately after falling in calm) 50-70 Damp new snow 100-200 Settled snow 200-300 Depth hoar 100-300 Wind packed snow 350-400 Firn   (granular snow) 400-830 Very wet snow and firn 700-800 Glacier ice 830-917

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