Snow

Different types of snowflakes

The albedo of an object is the extent to which it diffusely reflects light from the Sun. It is therefore a more specific form of the term reflectivity. Albedo is defined as the ratio of diffusely reflected to incident electromagnetic radiation.

Snowmaking is the production of snow by forcing water and pressurized air through a "snow gun" or "snow cannon", on ski slopes. Snowmaking is mainly used at ski resorts to supplement natural snow.

Blizzard is a severe storm condition characterized by low temperatures, strong winds, and heavy snow. The difference between blizzard and a snowstorm is the strength of the wind. Ground blizzards are a variation on the traditional blizzard, in that ground blizzards require high winds to stir up snow that has already fallen, rather than fresh snowfall. Regardless of the variety of blizzard, they can bring near-whiteout conditions, which restrict visibility to near zero.

Corduroy The resulting pattern on the snow after grooming is known as corduroy in ski and snowboard slang, and is widely regarded as a good - albeit unexciting - surface on which to ski or ride.

Constructive metamorphosis is caused by the upward movement of water vapor within the snow pack. Warmer temperatures are found closer to the ground because it receives heat from the core of the earth. Snow has a low thermal conductivity so this heat is retained creating a temperature gradient between the air underneath the snow pack and the air above it. Warmer air holds more water vapor.

Corn Snow or Spring Snow which is coarse, granular wet snow.

Cryosphere One of the earth's spheres of irregular form existing in the zone of interaction of the atmosphere, hydrosphere and lithosphere, distinguished by negative or zero temperature and the presence of water in the solid or super-cooled state; the term refers collectively to the portions of the earth where water is in solid form, including snow cover, floating ice, glaciers, ice caps, ice sheets, seasonally frozen ground and perennially frozen ground (permafrost).

Crown snow-load is snow and hard rime accumulating on tree crowns and structures in a cold climate. Hard rime is formed when droplets of fog or low level cloud (Stratus) freezes to the windward (wind-facing) side of tree branches, buildings, or any other solid objects, usually with high wind velocities and air temperatures between -2 °C (28 °F) and -8 °C (18 °F). Especially when a warm front brings wet snow, the surface of the tree is colder than the snowflakes, and the latter attach to the tree crown.

Deep Hoar Snow Large-grained, faceted, cup-shaped crystals near the ground. Depth hoar forms because of large temperature gradients within the snowpack.

Fresh Snow WSL Institute for Snow and Avalanche Research SLF Picture gallery CT-Images [1]]]

Deep Hore Snow WSL Institute for Snow and Avalanche Research SLF Picture gallery CT-Images [2]

Ice Crystals onto of Snow, from WSL Institute for Snow and Avalanche Research SLF Picture gallery CT-Images [3]

Wet Snow, from SLF WSL Institute for Snow and Avalanche Research SLF Picture gallery CT-Images [4]

Different Density of the snow Grains are represented by the different colors, from WSL Institute for Snow and Avalanche Research SLF Picture gallery CT-Images [5]

Faceted snow is angular snow with poor bonding created from large temperature gradients within the snowpack.

Firn — Old snow that has become granular and compacted (dense) as the result of various surface metamorphoses, mainly melting and refreezing but also including sublimation. The resulting particles are generally spherical and rather uniform.

Freezing Rain is Rain that falls as liquid and freezes upon impact to form a coating of glaze on the colder ground or other exposed surfaces.

Faceted snow is angular snow with poor bonding created from large temperature gradients within the snowpack

Frost is the solid deposition of water vapor from saturated air. It is formed when solid surfaces are cooled to below the dew point of the adjacent air as well as below the freezing point of water. Frost crystals' size differ depending on time and water vapor available. Frost is also usually translucent in appearance.

Glacier is a perennial mass of ice which moves over land. A glacier forms in locations where the mass accumulation of snow and ice exceeds ablation over many years. Columbia Icefields, Alberta Canada

Snow Squall is a heavy snow shower accompanied by sudden strong winds, or a squall. It is often referred to as a whiteout and is similar to a blizzard but is localized in time or in space and snow accumulations may or may not be significant.

Graupel is a form of frozen precipitation consisting of snowflakes or ice crystals and supercooled water droplets frozen together.

Ice Pellets is precipitation in the form of transparent or translucent pellets of ice, which are round or irregular in shape. They have a diameter of 0.2 inches (5 mm) or less. They are classified into two types: hard grains of ice consisting of frozen rain drops or largely melted and refrozen snowflakes; pellets of snow encased in a thin layer of ice which have formed from the freezing of droplets intercepted by pellets or water resulting from the partial melting of pellets.

The 0°C isotherm under normal conditions. Isotherm, represents the altitude in which the temperature is at 0°C (the freezing point of water) in a free atmosphere (i.e. allowing reflection of the sun by snow, etc.).

thumb|300px|Glacier ice is a compacted and intergrown mass of crystalline ice with a density of 830-910 kg·m-3

New Snow is recently fallen snow in which the original form of the snow crystals is recognizable. It is also considered to be the amount of snow fallen within the previous 24 hours.

Inversion A departure from the usual increase or decrease of an atmospheric property with altitude. It usually refers to an increase in temperature with increasing altitude, which is a departure from the usual decrease of temperature with height.

Permafrost or permafrost soil is soil at or below the freezing point of water (0 °C or 32 °F) for two or more years.

Rain crust is a type of snow crust formed by refreezing after surface snow crystals have been melted and wetted by liquid precipitation.

Snow Accumulation (also called snow depth.) A measurement of the depth of snow on the ground made either since the snow began falling or since a previous observation.

Rime is the rapid freezing of supercooled water droplets as they touch an exposed object, forming a white opaque granular deposit of ice. It is one of the results of an ice storm, and when formed on aircraft it is called rime icing.

Snow Drift is snow particles blown from the ground by the wind to a height of less than 2.0 meters / six feet.

Sastrugi are sharp irregular grooves or ridges formed on a snow surface by wind erosion and deposition, and found in polar and temperate snow regions. They differ from sand dunes in that the ridges are parallel to the prevailing winds. These words are plural: the singular is sastruga or zastruga. The word was taken from Russian.

Snow albedos can be as high as 90%; this, however, is for the ideal example: fresh deep snow over a featureless landscape. Over Antarctica they average a little more than 80%. If a marginally snow-covered area warms, snow tends to melt, lowering the albedo, and hence leading to more snowmelt (the ice-albedo positive feedback).

Sleet may refer to: Rain and snow mixed, particularly in countries where British English is spoken or Ice pellets, mainly within the United States.

Slush is Snow or ice on the ground that has been reduced to a softy watery mixture by rain and/or warm temperatures

A continuous, extremely slow, downhill movement of a layer of snow.

Snow is a type of precipitation in the form of crystalline water ice, consisting of a multitude of snowflakes that fall from clouds. The process of this precipitation is called snowfall.

Snowball is a spherical object made from snow, usually created by scooping snow with the hands, and compacting it into a roughly fist-sized ball. The snowball is often used to engage in games, such as snowball fights.

Snowfall is the process of precipitating snow is called snowfall. The rate at which snow falls, usually expressed in inches of snow depth over a six (6) hour period.

Snowball maker is a device used to make snowballs. Reduces issues with cold wet hands, soggy gloves or poorly packed snowballs.

Snow Banner is a plume of snow blown off a mountain crest, resembling smoke blowing from a volcano.

Snow Cover is the distribution of snow on the ground. The areal extent of ground covered by the snow. It is usually expressed as a percent of the total area of a given region. Snow cover in Scandinavia - photo from NASA [6]

A snow crystal is any of several types of ice crystal found in snow. A snow crystal is a single crystal, in contrast to a snowflake, which is usually an aggregate of many single snow crystals.]]

The basic structure of snow formed in the atmosphere is a hexagonal crystal. A-axes growth produces a stellar crystal or “snowflake”

Snow Devil is a small, rotating wind that picks up loose snow instead of dirt (like a dust devil) or water (like a waterspout). Formed mechanically by the convergence of local air currents. May be called a snowspout.

Colloquially an ice crystal, or more commonly an aggregation of many crystals that falls from a cloud.

Snow Garland is new snow appearing as a beautiful long thick rope draped on trees, fences and other objects. Formed by the surface tension of thin films of water bonding individual snow crystals.

The Snow line is the lowest elevation area of a perennial snow field on high terrain, such as a mountain range. The climatic snow line is the point above which snow and ice cover the ground throughout the year. The actual snow line may seasonally be significantly lower.

Ice pellets or Snow Pellets commonly occur with other crystal forms near the freezing point.

|Sun crust is a type of snow crust formed by refreezing after surface snow crystals have been melted by the sun.

Whiteout occurs when visibility is near zero due to blizzard conditions or occurs on sunless days when clouds and surface snow seem to blend, erasing the horizon and creating a completely white vista. Whiteout is a weather condition in which visibility and contrast are severely reduced by snow or sand. The horizon disappears and there are no reference points at all, leaving the individual without any orientation. It may be simply due to extremely heavy snowfall rates as seen in lake effect conditions, or due to other factors such as diffuse lighting from overcast clouds, mist or fog, or a background of snow.

Wind crust A type of snow crust formed by the packing action of wind on previously deposited snow. Wind crust may break locally, but, unlike wind slab, does not constitute an avalanche hazard.

Winter Storm is any one of several storm systems that develop during the late fall to early spring and deposit wintry precipitation, such as snow, freezing rain, or ice.

Snow Shower, is frozen precipitation in the form of snow, characterized by its sudden beginning and ending.

A plume of snow blown off a mountain crest, resembling smoke blowing from a volcano.

Whiteout occurs when visibility is near zero due to blizzard conditions or occurs on sunless days when clouds and surface snow seem to blend, erasing the horizon and creating a completely white vista. Whiteout is a weather condition in which visibility and contrast are severely reduced by snow or sand. The horizon disappears and there are no reference points at all, leaving the individual without any orientation. It may be simply due to extremely heavy snowfall rates as seen in lake effect conditions, or due to other factors such as diffuse lighting from overcast clouds, mist or fog, or a background of snow.

Winteris the astronomically, this is the period between the winter solstice and the vernal equinox. It is characterized as having the coldest temperatures of the year, when the sun is primarily over the opposite hemisphere. Winter and snow cover over North America in the winter.

Winter Storm is any one of several storm systems that develop during the late fall to early spring and deposit wintry precipitation, such as snow, freezing rain, or ice.