=> Entrainment of air outside into the cloud 
=> Evaporation of cloud droplets 
=> Evaporative cooling initiates a cool downdraft in the cloud 
=> Falling hydrometeors (raindrops) in the downdraft below cloud base evaporate 
=> Evaporative cooling of raindrops in rainshaft counters adiabatic warming

Summer and early fall weather in Southern California is marked by persistent
=> Sunny skies
=> Warm afternoon temperatures that promotes development of photochemical smog
=> Modest wind speeds with a persistence PM sea breeze that impedes horizontal transport
=> Strong inversion from the combination of subsidence from the Pacific High and cool sea breeze that limits vertical dispersion

=> Warmer winter temperatures that remain below freezing
=> Higher saturation vapor pressure than colder winters
=> More snowfall potential
=> More ice build up and glacial advance