Forms of precipitation

i. Rain: It is the most common form of the precipitation consisting of liquid water droplets bigger than 0.5mm in diameter.

ii. Drizzle: It is fairly uniform precipitation composed exclusively of fine droplets of water diameter <0.5mm and very close to one another. When drizzle occurs, relative humidity of air is often nearly 100%. So fine drops never evaporate in their journey.

Frozen forms of precipitation include snow, ice needles, sleet, hail, and graupe.

iii. Snow: Precipitation in the form of ice crystals resulting from the direct conversion of water vapor to ice is referred as snow. Usually in winter, when temperature is below freezing in the whole atmosphere, the ice crystal doesn’t melt and reach the ground as snow. Actually, on very cold atmosphere sublimation of water vapor leads to snow. It is the precipitation of white and opaque grains of ice in the form of hexagonal crystals.

iv. Sleet: Sleet is a weather phenomenon that occurs mostly in winter storms. The clouds where the sleet falls from are warmer than the air below. The sleet begins as rain and, as it falls, freezes, becoming rather small ice pellets. Sleet is a mixture of rain and snow. However, in American terminology, it is the small pallets of translucent ice <0.5 mm in diameter.

v. Hail: Hail is a weather phenomenon occurring in summer storms. Rain falls from the warmer bottom of storm clouds. Updrafts in the storm lift the rain to the upper, colder regions of the storm clouds, causing the rain to freeze. Hails are usually 5 mm or more in diameter. Anything smaller is considered an “ice pellet“. It is precipitation of small balls or piece of ice with a diameter ranging from 5-50 mm or even more.

vi. Dew: Sometimes, moisture is made available at soil surface by direct condensation and absorption from the atmosphere. This is known as dew and it is observed that mostly it evaporates as the day progress.