The Snow Effect procedural texture produces a blurry snow-like pattern (figure 1).
Figure 1: The Snow Effect node and it's associated parameters
Time - Provides control over animating the texture effect.
Radius - Determines the size of the snow flakes.
Flake Count - Specifies the number of snow flakes.
Blizzardness - Determines the direction and shape of the snow flakes.
Transform Input - Positions, scales, and rotates the surface texture.
Projection Input - Sets how the texture projects onto the surface.