Clouds and PrecipitationBlaine Cooper

Adiabatic Temperature Changes

This is when the temperature changes but heat is not added or subtracted.

This happens because air is compressed or allowed to expand.

Expansion and Cooling Unsaturated air cools at a rate of

10 degrees Celsius for every 1,000 meters of ascent.

This also works vise versa.

Orographic Lifting

This is when elevated terrains act as barriers to air flow.

Frontal Wedging In central North America warm air

masses and cold collide, producing a front.

The cooler, denser air acts as a barrier over which the warmer, less dense air rises.

Convergence

This is when air in the lower atmosphere flows together and causes air lifting.

Localized Convective Lifting The process when convection

warm air rises over a particular local area.

Glider pilots study these to know where to fly.

Stability

Stability resists vertical movement.

It is also a large part in the predicting of daily weather.

Condensation

This is the change of physical state of matter.

It is a change from the gaseous phase into a liquid phase.

Types of Clouds There are four types of clouds

There is the Stratus clouds

The Altostratus clouds

The Cirrus clouds

And the Cumulus clouds

High Clouds High clouds are also known as the

Cirrus clouds

They do not produce precipitation

They are the highest clouds in the atmosphere.

Medium Clouds These are the Altostratus clouds.

They have water droplets or ice crystals.

They are also very thin.

Low Clouds The low clouds are the Stratus clouds

They produce a light drizzle or snow

They are the lowest in the atmosphere, and are known to be flat.

Clouds of Vertical Development

The vertical clouds are Cumulus.

These clouds look puffy and cotton like.

They are also associated with hail, waterspouts, and tornadoes.

Fog

Liquid droplets suspended in air near surface.

Cold Cloud Precipitation This is also known as the Bergeron

process.

It is the formation of precipitation by ice crystals.

Warm Cloud Precipitation The theory of raindrop formation in

warm clouds.

Large cloud droplets collide and join together.

Known as the Collision – Coalescence process.

Rain and Snow Precipitation composed of rain and

partially melted snow.

This occurs when temperatures are slightly above freezing point.

Sleet, Glaze, and Hail Could occur in an ice storm, freezing

rain, and/ or glaze event.

This can occur only when temperatures are below the freezing point.