Rain

Precipitation includes all forms of additional water, in the liquid or solid state, that fall or form on the Earth’s surface.
They can be subdivided into direct precipitation, such as rain, snow and hail and occult precipitation, such as dew and frost, that do not derive from clouds but form directly on contact with the Earth’s surface.
Liquid precipitation, or rain, takes place when drops of water present in a cloud grow bigger and bigger until they are too heavy to remain in the cloud and therefore fall to the ground.
The mechanisms by which the cloud drops grow bigger are several: by absorbing water in an over-saturated atmosphere or, specially by coalescence, that occurs when drops collide against each other on falling.
The limit that separates cloud drops from rain drops is around 100 micron, but generally rain drops are much bigger, at times greater than 2000 micron.

Special reports

  • 29 April 2020

    Lightning

    Man has always been afraid of lightning, in fact in the past lightning was considered a sign of the anger…

  • 7 July 2010

    What is the weather like?

    On a beautiful, sunny summer day you may...

  • 11 December 2013

    Typhoons, hurricanes and cyclones

    On November 8, 2013 typhoon Haiyan hit the Philippines with winds...

From the Multimedia section

Facts