SCIENCE REPORT - Snow Facts

SCIENCE REPORT
–
January 16, 2002: Snow Facts

By George Grow

This is the VOA Special English SCIENCE REPORT.

Winter weather has arrived in northern areas of the world. In much of the United States, winter means the return
of snow. Last month, during a severe storm, about two meters of snow fell on the city of Buffalo¹, New York.

Snow is a subject of great interest to weather experts. Experts sometimes have difficulty
estimating where, when or how much snow will fall.

Snow is a form of frozen² water. It contains many groups of tiny ice particles, called snow
crystals. These crystals grow from water particles in cold clouds. They usually grow around a
piece of dust. All snow crystals have six sides, but they grow in different shapes. The shape Snow storm in
depends mainly on the temperature and water levels in the air. Buffalo

Snow crystals grow in one of two designs --platelike and columnar. Platelike crystals are flat. They form when
the air temperature is about fifteen degrees below zero Celsius³. Columnar snow crystals look like sticks of ice.
They form when the temperature is about five degrees below zero Celsius.

The shape of a snow crystal may change from one form to another as the crystal passes through levels of air with
different temperatures. When melting snow crystals or raindrops fall through very cold air, they freeze to form
small particles of ice, called sleet⁴.

When snow crystals stick together, they produce snowflakes. Snowflakes come in different sizes. As many as
one-hundred crystals may join together to form a snowflake larger than two-and-one-half centimeters. Snow
contains much less water than rain. About fifteen centimeters of wet snow has as much water as two-and-one-half
centimeters of rain. About seventy-six centimeters of dry snow equals the water in two-and-one-half centimeters
of rain.

Each year, the continental⁵ United States has an average of one-hundred snow storms. An average storm produces
snow for two to five days. Almost every part of the country has received snowfall at one time or another. Even
parts of southern Florida have reported a few snowflakes.

Snow creates many problems for people traveling. But it also is important. Much of the water we use comes from
snow. Melting snow provides water for rivers, electric power centers and agricultural crops. In the western
United States, mountain snow provides up to seventy-five percent of all surface water supplies.

This VOA Special English SCIENCE REPORT was written by George Grow.

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1 buffalo   

n.(北美)野牛；(亚洲)水牛

参考例句：

• Asian buffalo isn't as wild as that of America's. 亚洲水牛比美洲水牛温顺些。
• The boots are made of buffalo hide. 这双靴子是由水牛皮制成的。

2 frozen   

adj.冻结的，冰冻的

参考例句：

• He was frozen to death on a snowing night.在一个风雪的晚上，他被冻死了。
• The weather is cold and the ground is frozen.天寒地冻。

3 Celsius   

adj.摄氏温度计的，摄氏的

参考例句：

• The temperature tonight will fall to seven degrees Celsius.今晚气温将下降到七摄氏度。
• The maximum temperature in July may be 36 degrees Celsius.七月份最高温度可能达到36摄氏度。

4 sleet   

n.雨雪；v.下雨雪，下冰雹

参考例句：

• There was a great deal of sleet last night.昨夜雨夹雪下得真大。
• When winter comes,we get sleet and frost.冬天来到时我们这儿会有雨夹雪和霜冻。

5 continental   

adj.大陆的，大陆性的，欧洲大陆的

参考例句：

• A continental climate is different from an insular one.大陆性气候不同于岛屿气候。
• The most ancient parts of the continental crust are 4000 million years old.大陆地壳最古老的部分有40亿年历史。