air, its relative humidity increases until saturation occurs (100 percent relative humidity). What if … air. These include relative humidity and dew-point temperature. Relative Humidity The most familiar and … describe the moisture content of air is relative humidity. Relative humidity is a ratio of the air’s actual water-vapor

the dry adiabatic lapse rate causes it to reach complete saturation (i.e. a relative humidity of 100 percent). If the parcel is lifted further beyond the This glossary of meteorology is a list of terms and concepts relevant to meteorology and atmospheric science, their sub-disciplines, and related fields. lifting condensation level (LCL) Also lifted condensation level. The altitude to which a parcel of air must be raised or lifted before expansional cooling at the dry adiabatic lapse rate causes it to reach complete saturation (i.e. a relative humidity of 100 percent). If the parcel is lifted further beyond the LCL, water vapor within…

convection as air warmed by the surface begins to rise. As the air rises, the temperature drops (following the lapse rate), causing the relative humidity (RH) Cumulus clouds are clouds that have flat bases and are often described as puffy, cotton-like, or fluffy in appearance. Their name derives from the Latin cumulus, meaning "heap" or "pile". Cumulus clouds are low-level clouds, generally less than 2,000 m (6,600 ft) in altitude unless they are the more vertical cumulus congestus form. Cumulus clouds may appear by themselves, in lines, or in clusters. Cumulus clouds form via atmospheric convection as air warmed by the surface begins to rise. As the air rises, the temperature drops (following the lapse rate), causing the relative humidity (RH) to rise. If convection reaches a certain level the RH reaches one hundred percent, and the "wet-adiabatic" phase begins. At this point a positive feedback ensues: since the RH is above 100%, water vapor condenses, releasing latent heat, warming the air and spurring further convection. In this phase, water vapor condenses on various nuclei present in the air, forming the cumulus cloud. This creates the characteristic flat-bottomed puffy shape associated with cumulus clouds. The height of the cloud (from its bottom to its top) depends on the temperature profile of the atmosphere and of the presence of any inversions. During the convection, surrounding air is entrained (mixed) with the thermal and the total mass of the ascending air increases. Rain forms in a cumulus cloud via a process involving two non-discrete stages. The first stage occurs after the droplets coalesce onto the various nuclei. Langmuir writes that surface tension in the water droplets provides a slightly higher pressure on the droplet, raising the vapor pressure by a small amount. The increased pressure results in those droplets evaporating and the resulting water vapor condensing on the larger droplets. Due to the extremely small size of the evaporating water droplets, this process becomes largely meaningless after the larger droplets have grown to around 20 to 30 micrometres, and the second stage takes over. In the accretion phase, the raindrop begins to fall, and other droplets collide and combine with it to increase the size of the raindrop. Langmuir was able to develop a formula which predicted that the droplet radius would grow unboundedly within a discrete time period.