NASA explains why it drizzles instead of raining sometimes
A NASA study explains updrafts, upward currents of air, play an important role in determining why clouds sometimes produce drizzle instead of full-sized raindrops. Researchers found these updrafts in low-lying clouds can curtail drizzle by pushing droplets into upper clouds. These drops remain airborne until they coalesce to form full-sized droplets, eventually causing rainfall, they added.