a rate of many inches of snow each hour, often resulting in a large amount of total snowfall. The areas affected by lake-effect snow are called snowbelts. These include areas east of the Great Lakes, the west coasts of northern Japan, the Kamchatka Peninsula in Russia, and areas near the Great Salt Lake, Black Sea, Caspian Sea, Baltic Sea, and parts of the northern Atlantic Ocean. Mountain effects Orographic or relief snowfall is created when moist air is forced up the windward side of mountain ranges by a large-scale wind flow. The lifting of moist air up the side of a mountain range results in adiabatic cooling, and ultimately condensation and precipitation. Moisture is gradually removed from the air by this process, leaving drier and warmer air on the descending, or leeward, side. The resulting enhanced snowfall, along with the decrease in temperature with elevation, combine to increase snow depth and seasonal persistence of snowpack in snow-prone areas. Mountain waves have also been found to help enhance precipitation amounts downwind of mountain ranges by enhancing the lift needed for condensation and precipitation. Cloud physics A snowflake consists of roughly 1019 water molecules which are added to its core at different rates and in different patterns depending on the changing temperature and humidity within the atmosphere that the snowflake falls through on its way to the ground. As a result, snowflakes differ from each other though they follow similar patterns. Snow crystals form when tiny supercooled cloud droplets (about 10 μm in diameter) freeze. These droplets are able to remain liquid at temperatures lower than , because to freeze, a few molecules in the droplet need to get together by chance to form an arrangement similar to that in an ice lattice. The droplet freezes around this "nucleus". In warmer clouds, an aerosol particle or "ice nucleus" must be present in (or in contact with) the droplet to act as a nucleus. Ice nuclei are very rare compared to cloud condensation nuclei on which liquid droplets form. Clays, desert dust, and biological particles can be nuclei. Artificial nuclei include particles of silver iodide and dry ice, and these are used to stimulate precipitation in cloud seeding. Once a droplet has frozen, it grows in the supersaturated environment—one where air is saturated with respect to ice when the temperature is below the freezing point. The droplet then grows by diffusion of water