When moist air passes over land surfaces that have been strongly heated, the air is forced to rise and the condensation process begins.

When two large air masses come together or converge, the air is forced to rise and the condensation process commences.

The daily range of temperature or other weather elements.

The average number of months where the average precipitation is greater than evapo-transpiration.

Rainfall that is associated with the passage of a front over a location.

Outgoing radiation from the earth's surface - sometimes referred to as terrestrial radiation.

When moist air is forced to rise up over a mountain range in its path.

Heat in wave form sent out by the sun or earth.

Evaporation and transpiration from a land or plant source. Water changes from a liquid to a gas through heating of the water surface. Heat is trapped within the vapour (latent heat). Vapour rises in the air. Temperature decreases, condensation begins to occur, relative humidity starts to increase (if the relative humidity reaches 100% condensation occurs as the . air becomes saturated with moisture). Condensation takes place in the atmosphere- at a level called condensation level. The temp at which condensation occurs is called the dew point Water droplets become to heavy to be suspended in the cloud–they hen fall out of the cloud as rain.

The water, which does not soak into the ground or is used by plants, animals and people, runs off the surface into streams, river and lakes.

Incoming radiation from the sun.

This is a comparison of the energy gained and lo t (inputs and outputs of energy).