Precipitation

Precipitation is all form of water that reaches the earth surface form atmosphere. Precipitation can be in solid form or in liquid form. The usual forms of precipitation are rainfall, snow, hail, frost, dew etc

Forms of precipitation :

1. Rainfall : Precipitation  in form of water of size later than 0.5mm is called rainfall. The maximum size of raindrop is about 6mm. Any drop larger than this size tends to breakup into drop of smaller size during its fall from the cloud. On the basis of its intensity rainfall can be classified as

       Type                          Intensity
1. Light Rain               trace to 2.5 mm/hr
2. Moderate Rain        2.5mm/hr to 7.5 mm/hr
3. Heavy Rain              grater than 7.5 mm/hr

2. Snow : Snow is another important form of precipitation consisting ice crystal usually combined to form flukes. Snow is white in color and fluffy while touching and falls in cold region where usually temperature is low for most part of year and where temperature goes below 0'C.

3. Drizzle : A fine sprinkle of numerous water droplets of size less than 0.5mm and intensity less than 1mm/hr is known as drizzle. In drizzle, drops of water are so small that they appear to float in air.

4. Glaze : When rain or drizzle comes in contact with cold ground at around 0'C, the water drop freeze to form an ice coating called glaze and freezing rain.

5. Sleet : It is frozen rain drops of transparent grains which forms when rainfalls through air at sub freezing temperature. In Britain, sleet denotes precipitation of snow and rain simultaneously.

6. Hail : It is showery precipitation in form of irregular pallets of size more than 8mm. hail occurs in violent thunderstorm in which vertical current very strong.

7. Frost or dew : Consolidation that occurs at the ground surface at night,