Javlin wrote:
My misunderstanding been awhile since my studies but had to consider Air as a fluid in the past figuring equations so I figured you add more moisture then you would increase weight.Warm modecules move quicker than cold/cold heavier maybe two lines of thought are diverging?
ozonepete and psyclone are correct. Moist air (air with water vapor) is less dense and therefore more buoyant than the same amount of dry air at the same temperature, though this effect alone is not enormous. This is because water vapor molecules are lighter (on a per-molecule basis) than the two other main constituents of air, oxygen and nitrogen molecules. What also makes thunderstorm updrafts so buoyant is the fact that the condensation of water vapor as cloud forms within them releases a large amount of heat (the so-called "latent heat of condensation") which helps counteract the cooling that occurs as the updraft expands while rising. This latent heat release is the main driver of a deep convective updraft.