The Elements

Precipitation

Precipitation is any form of water falling from the atmosphere to the Earth’s surface. It is the process by which atmospheric water becomes surface, or subsurface water. The term "precipitation" [...]

How do droplets form?

Water is available on the Earth in the following three forms: vapor, liquid and solid. A phase change (water changing from one state to another) is possible only if heat [...]

Formation Models of Precipitation

Most clouds do not precipitate. In fact, most water droplets in clouds have such a small size that they do not fall to the surface. There are two models, developed by [...]

Forms of precipitation

We have stated that, from a meteorological point of view, precipitation is water in some form, falling out of the air, and settling on the surface of the Earth. We [...]

Precipitation Measurement

Precipitation quantity or precipitation amount is the depth of water in any of its forms (rain, snow, etc.) that has fallen over a given period; it is measured in a [...]

Cloud Seeding

Cloud seeding is a form of weather modification. It can be used to disperse fog, suppress hail, or control winds, but it is most often used to increase precipitation. Cloud seeding [...]

Clouds

A cloud is a hydrometeor, seen as an aggregate of minute particles of liquid water or ice, or of both, suspended in the free air, usually not touching the ground. [...]

Formation of clouds

Clouds are created by condensation or deposition of water above the Earth's surface. In general, any air mass that becomes saturated (relative humidity becomes 100%) develops clouds. Saturation can occur due to: cooling moisture gain (from Earth´s surface [...]

Classification of clouds

Clouds are classified according to appearance and height. Based on appearance, there are two major types: Clouds of vertical development, cumuliform, formed by the condensation of rising unstable air –heaped clouds-. Clouds that [...]

Winds (mainly surface)

Wind: air in motion relative to the surface of the Earth. Vertical components of atmospheric motion are relatively small, so the term is used to denote almost exclusively the horizontal [...]

Formation of winds

Different forces acting in the atmosphere are involved in wind formation: Gravity - makes cold dense air to sink and when it impacts on the ground, it spreads horizontally. Pressure - differences [...]

Types of winds

There are different types of winds: Light air: Light air in the Beaufort wind scale is a wind with a speed from 1 to 3 knots (1 to 3 MPH or 2 [...]

Measurements

Beaufort wind scale: - A system of estimating and reporting wind speeds using a numerical scale ranging from 0 (calm) to 12 (hurricane). - The purpose for this system was to allow [...]