Snowing

Snowing refers to precipitation in the form of snow, consisting of ice crystals formed in clouds when atmospheric conditions allow. Snow typically reaches the ground when air temperatures near the surface are at or below freezing, and there is sufficient humidity for ice crystals to survive en route downward.

Snow forms as water vapor in clouds deposits directly onto microscopic nuclei, growing as crystals that eventually join to create snowflakes. The fine details of a snowflake depend on temperature and humidity: moderate humidity near freezing yields complex, dendritic shapes; very cold, dry air tends to produce smaller, simpler crystals; and warmer conditions near 0 °C can produce wetter, heavier snow that is more prone to melting or compression.

Snowfall is described by its rate and the resulting accumulation. Common categories include light snow or flurries, regular snowfall, and heavy snowfall or snowstorms. Snow can also occur in showers or squalls, with brief but intense bursts. Strong winds with falling snow can create blizzard conditions by reducing visibility and drifting.

Ground conditions influence whether snow accumulates. Temperature, wind, solar radiation, and underlying surface affect whether snow remains, compacts, or melts. Snowpack insulates the ground, stores freshwater, and affects soil processes, while rapid melting can contribute to flooding. Snow depth and water equivalent are standard measures reported by meteorological agencies.

Snow events affect transportation, infrastructure, and daily life, and support winter recreation and regional water resources in some areas. Snow cover is also a tracer of climatic patterns and variability.