Snow vs ice?

Question

What is the difference between snow and ice? I am not asking visible difference but how it is formed? What happens up there in the air that triggers a snow fall or an ice storm or just plain rain? I guess all need humid air.

Answer 1

Good question irobot and this is how I just answered a similar question regarding freezing rain (an ice storm).



This is how it works. Draw the following vertical temperature profile. Draw a line to represent the surface and a vertical line to represent 0 degrees centigrade. Finally, draw the following temperature profile. From the surface draw a curve starting from the left of the O degree line upwards to the right so it crosses the 0 degree line and continues for a short distance beyond before turning to the left and once again crossing the 0 degree line and continuing with height. This gives us three layers of atmosphere. In the top layer below freezing it is snowing. When this snow falls into the next lower layer which is above freezing it melts into rain. And finally when the rain falls into the lowest layer below freezing it becomes freezing rain and coats everything it lands on becoming an ice storm.

It is very important that the bottom freezing layer is shallow, because if it is a deep layer, the freezing rain will become sleet and if the bottome layer and there is only a warm lower layer the precipitation will be all rain. But all precipitation except that in the tropics begins as snow in that cold layer aloft.

Answer 2

Much of the rain that falls is first formed as snow at very high (cold) elevations then melts on the way down (even in summer). An ice storm may occur when the snow only melts to freezing point on the way down and may even super-cool because it is so pure. When the drops hit a metal surface the melt drains away leaving a coating of ice (often on windshields!). Ice is usually formed when a body of water falls to freezing and heat is lost from the upper layer. All the warmer water below must rise and cool to freezing before ice can form on a pond (known as turnover). As water freezes, the polar water molecules bind in chains that use up space less efficiently than liquid water causing ice to expand, become less dense and float on liquid water. About a tenth of the volume of an iceberg floats above water although a melted iceberg will exactly fill the 'hole' it makes in the water. The volume of the water has expanded about 10% to form ice. Ice is also formed when snow becomes highly compacted (as on a glacier) and its air contant may differ from pond ice. When pond ice forms, growing ice crystals exclude any foreign matter which winds up trapped between grains of ice. At springtime, the boundaries between ice grains melt first causing weakened 'rotten' ice that looks much stronger than it really is.

Answer 3

Ice
Ice is the name given to any one of the 14 known solid phases of water. In non-scientific contexts, it usually describes ice Ih, which is the most abundant of these phases. It is a crystalline solid, which can appear transparent or an opaque bluish-white color depending on the presence of impurities such as air. The addition of other materials such as soil may further alter appearance.
The most common phase transition to ice Ih occurs when liquid water is cooled below 0 °C (273.15 K, 32 °F) at standard atmospheric pressure. It can also deposit from a vapor with no intervening liquid phase, such as in the formation of frost.
Ice appears in nature in varied forms such as hail and glaciers. It plays an important role with many meteorological phenomena. The ice caps of the polar regions are of significance for the global climate and particularly the water cycle. It has many applications.


Snow
Snow is a type of precipitation in the form of crystalline water ice, consisting of a multitude of snowflakes that fall from clouds. Since snow is composed of small ice particles, it is a granular material. It has an open and therefore soft structure, unless packed by external pressure.


Snow: http://en.wikipedia.org/wiki/Snow
Ice: http://en.wikipedia.org/wiki/Ice

Answer 4

Freezing rain or ice falling to the ground is actually melted snow that has froze again. Read my article for an expanation: http://weatherforecasting.suite101.com/article.cfm/forecasting_precipitation_types

Answer 5

....Simply put : snow = tempertures cold enough for snow. ice = tempertures not quite cold enough for snow, but not warm enough for rain.

if you would like a lengthy meterologist stand point let me know!

Answer 6

SNOW IS SNOW AND ICE IS ICE!!!