text: First you need a parcel of warm moist air. Since warm air is less dense than cold it will rise.\n\nWhen it rises through the troposphere, the air will cool due to something called the adiabatic cooling process. This just means that as air pressure is reduced, the air particles will not be compressed any longer & will cool. \n\nThink of adiabatic temperature change like a bicycle pump. If you keep pumping it, what happens to the cylinder? It gets much warmer. This is b/c you are compressing the air. In the opposite way, w/ certain types of aerosol cans, continuously holding down the nozzle causes the can to cool. This is b/c you are allowing the trapped gases to expand.\n\nWhen the moisture laden air parcel cools to the dew point, water vapor will condense on tiny particulates suspended in the atmosphere. These particles are referred to as condensation nuclei or aerosols. These are usually one of the following: pollen, dust, ash, pollution, salts, etc.\n\nA good way to think of this is an ice cold cola can. On a hot day, moisture from the air surrounding the can will condense on the outside. This is b/c the cold drink inside the can allows the air on the outside to reach the dew point.\n\nOnce condensed on these particles, you have the makings of a cloud!