SkyStef's weather page
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SkyStef's weather page |
Weather picture of the month March 2005
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| Picture taken at Kampenhout on February 24 2005. |
| Definition of snow
= precipitation of ice crystals, singly or
agglomerated,
which falls from a cloud. Depending on the temperature and moisture that prevails during formation and descent, snow crystals may grow into the form of plates, stellar crystals, columns, needles or dendrites - all of which are based on the hexagonal lattice structure. An individual snow crystal may range in diameter size from less than 0,5 mm to more than 4,0 mm. Aggregations of two or more of these crystals form a snowflake. This agglomeration usually occurs with temperatures higher than about -5°C. A fall of snow usually includes various types of snow crystals and almost all types of crystals may be observed during a single fall of snow. Small droplets of frozen water are often attached to snow crystals. When there are few of these droplets the crystalline structure is still very visible, when there are many, the structure is scarcely visible any more. The picture shows a magnified falling snowflake catched at night with flashlight under calm air conditions. Surrounding temperature was -1°C on ground, -10°C at 850 hPa and -18°C at 700 hPa. A closer inspection of this snowflake revealed that it was an aggregation of stellar crystals. A composition of other falling snowflakes on this occasion can be found via this weather report |
