Snowflakes are small and their structure is simple at very low temperatures. At higher temperatures the distinct flakes may be formed from a very large amount of ice crystals - creating a complex star shape and can have a diameter of several inches. (Met Office, 2014)
Snowflakes are accretions of several snow crystals. Most snowflakes are less than 1.3 centimetres (0.5 inches) through. Under some conditions, usually needing near-freezing temperatures unstable atmospheric conditions, and light winds, much larger and asymmetrical flakes can form, nearing 5 centimetres (2 inches) across. No predictable size of snowflake dimensions are taken, so the exact size is not known. (National Snow and Ice Data Center, 2017)
1.2.4: Types of Snow:
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Although an avalanches can take place (given the required environment) on any slope, certain locations and certain times of the year are usually more hazardous than others. Most avalanches are likely to happen during wintertime, chiefly from December to April. However, fatalities due to avalanches happen all year.
Only thing that is needed for an avalanche to form is a large bulk of snow and a slope for it to slide down. There are avalanches on many scales, from small to large. Mountain avalanches are big and the conditions that cause them to occur are very complicated. In North America, a big avalanche might release 230,000 cubic meters (300,000 cubic yards) of snow. However, such large avalanches are usually released in natural way, when the snowpack becomes unsteady and layers of snow cannot support themselves. Skiers and recreationalists usually initiate slighter, but every so often more lethal avalanches.
An avalanche consists of three key portions. The most instable region of a slope is the starting zone, where unstable snow cracks from the adjacent snow cover and starts to slide. Distinctive starting zones are usually on the higher slopes. However, snow can break at any point on the slope under the right