This mod includes the following features:
Snow can exist on ice and grass paths;
Snow melts faster indoors;
Multi-layered snow melts by reducing the number of layers instead of disappearing altogether;
Snow can fall in multiple layers;
Multi-layered snow spreads at random ticks;
Snow replaces plants with the REPLACEABLE_PLANTS tag when it snows;
Grass blocks can survive under multi-layered snow;
Each feature can be controlled by the corresponding gamerule to enable and probability.

