This helps suggest the birth of a storm on the verge of an imminent deluge. Keep in mind that some raindrops will catch and reflect light while others block it and appear dark. Snow can be illustrated by using blue and Ice blue markers on white paper, which serves as a base color. Wispy streaks of snow or flakes themselves can be introduced with white dots or smeared streaks from a brush. Cool and basic grays can be used to illustrate dark and angry skies.
Markers are effectively versatile, portable, and fun to use.
If you haven't worked with markers yet, try them and see the results for yourself.