One day while watching the rain come down in small steady drops, I wondered if a cloud was to 'release' all it's water in one instance, what would happen to us standing underneath? Was there enough water up there to cause massive damage down here, much like a river bursting it's banks? Or was it more the case that the water was very low density (water droplets are typically 0.01mm in diameter) and that clouds were mainly 'nothing'?
Today I got a peak at some of the numbers involved thanks to Robert Krulwich (of WYNC Radiolab fame). In his piece "How Much Does A Hurricane Weigh?" Robert tells us that an average storm cloud contains around 105,800,000 (105 million) lbs of water - about 48,000 tonnes.
With that kind of water volume falling from thousands of feet above I think the next time you want to complain about getting drenched in the rain, remind yourself that there's three hundred and fifty Blue Whales worth of water hanging perilously above your head and a few rain drops probably aren't so bad.
Oh, and how much does a hurricane weigh? An average North American hurricane contains about 108,000,000,000 (108 billion) lbs of water - about 48 million tonnes. In Blue Whales, that's about 360,000.
Notes:  http://en.wikipedia.org/wiki/Cloud