Collection: Snow

Snow refers to forms of ice crystals that precipitate from the atmosphere (usually from clouds) and change shape on the Earth's surface.[2] It is frozen crystalline water throughout its life cycle, which begins with the ice crystals forming in the atmosphere under suitable conditions, growing to millimeter sizes, precipitating and accumulating on surfaces, then metamorphosing in place and finally melting, sliding off, or sublimating. Blizzards organize and develop by feeding on sources of atmospheric moisture and cold air. Snowflakes form around particles in the atmosphere by attracting supercooled water droplets that freeze into hexagonal crystals. Snowflakes take on a variety of shapes, including platelets, needles, columns, and frost. When the snow accumulates into a blanket, it can blow into drifts. Over time, the accumulated snow transforms through sintering, sublimation, and freeze-thaw cycles. Where the climate is cold enough to allow seasonal accumulation, a glacier may form. Otherwise, snow typically melts seasonally, flowing into streams and rivers and recharging groundwater.