### Symbols and Notations used in Snow Loads Design Data

This is a list of symbology used in related snow loads design and engineering webpages.

Ce = exposure factor as determined from Table E-2
Cs = slope factor as determined from Fig. E-2
Ct = thermal factor as determined from Table E-3
hb = height of balanced snow load determined by dividing ps by γ , in ft (m)
hc = clear height from top of balanced snow load to (1) closest point on adjacent upper roof, (2) top of parapet, or (3) top of a projection on the roof, in ft (m)
hd = height of snow drift, in ft (m)
ho = height of obstruction above the surface of the roof, in ft (m)
I = importance factor as determined from Table E-4
lu = length of the roof upwind of the drift, in ft (m)
L = roof length parallel to the ridge line, in ft (m)
pd = maximum intensity of drift surcharge load, in lb/ft2(kN/m2)
p f = snow load on flat roofs (“flat” = roof slope ≤ 5◦), in lb/ft2 (kN/m2)
pg = ground snow load as determined from Fig. 7-1 and Table E-1; or a site-specific analysis, in lb/ft2 (kN/m2)
ps = sloped roof snow load, in lb/ft2 (kN/m2)
s = separation distance between buildings, in ft (m)
S = roof slope run for a rise of one
θ = roof slope on the leeward side, in degrees
w = width of snow drift, in ft (m)
W = horizontal distance from eave to ridge, in ft (m)

γ = snow density, in lb/ft3 (kN/m3) as determined from Eq. E-3 but not less than the following minimum values for low slope roofs.

Where:

pg is 20 lb/ft2 (0.96 kN/m2) or less,
pf = (I ) pg (Importance factor times pg)

Where:

pg exceeds 20 lb/ft22 (0.96 kN/m2),
pf = 20(I ) (20 lb/ft2 times Importance factor)