The same is true for objects with thermal mass that retain heat or cold after a sudden change in air temperature.
Surface properties such as roughness.
If even a few snow flakes find purchase on a surface, more will find a way to build on that and obscure your surface. This is far more important than angle.
Atmospheric conditions such as humidity and the nature of the snow flakes formed.
To effectively keep a surface clear it should be ① smooth, ② quickly transfer heat to adapt to the current air temperature, and ③ be sheltered from being in contact with falling snow in the first place. Even highway signs with are smooth, vertical and thin metal are only so effective at staying clear and in some regions will have eaves protecting them from some snowfall.
increased at higher temperatures, between −15 and −5, and even more between −5 and −2°C.
Often, sintering is discussed in close connection to friction, which constitutes another temperature-dependent process for ice. However, its role in the angle of repose is not clear. While it is the key parameter in Mohr–Coulomb theory, which is often used for a theoretical analysis of the angle of repose (MCGlinchey, Reference McGlinchey2005), other studies conclude that friction plays a sub-dominant role behind particle shape and cohesion, and can therefore be neglected (Nowak and others, Reference Nowak, Samadani and Kudrolli2005).
The picture below is taken from the article. Particle with a smoother shape have a lower angle of repose; the bottom set of blue lines with an angle of repose around 20°. The more angular the shape of the particles, the higher the angle of repose; the yellow and green lines with an angle of repose around 30° to 40°, depending on temperature. In both of these situations, the angle of repose increase with temperature.
The fact that snow can deposit on a vertical surface would indicate the snow particles would be angular and would have a degree of sintering.
