Snow

Snow slows a frame down. The particles drift instead of falling, so the air has movement in it that takes its time, and the shot feels quieter than the same shot in clear weather.

It also flattens the world. Accumulation covers detail, the ground goes bright, and a landscape loses its texture until only shapes are left.

Flake size is the weather. Fine dry snow moves fast and nearly sideways in wind. Large wet flakes fall slowly and stick to everything. Those two look like different days.

The exposure problem runs the opposite way from rain. Snow on the ground is bright, so a camera set for the ground underexposes faces and a camera set for faces blows the ground out. Bounce is the usual fix, because the accumulation works as a huge soft source from below.

Backlight still helps. A source behind the fall separates the flakes from a dark background, and the same source against a bright sky loses them.

Use it for isolation, for cold, and for a scene where you want the pace of the frame to drop.

Skip it when the shot needs texture and contrast on the ground, because accumulation takes both away.

Rain falls fast and straight and makes surfaces reflective. Snow drifts and makes them bright and matte. The reflection under the subject tells you which one you are in.

Fog erases the background. Heavy snow does the same at a distance, so if the far planes are gone and nothing is falling in the foreground, you have asked for fog.

Joel and Ethan Coen open Fargo (1996) on falling snow with no horizon in it, and a car arrives out of a white field before the film gives the audience anything else to look at.

Every result is the same medium snowfall. Name the flake size and the speed, because fine and heavy read as different weather and the model will average them.

The second failure is snow in the air above clean dry ground. Ask for accumulation on the surfaces and say roughly how deep it is.