1Two things hiding inside a storm cloud
It's freezing up top — and the hot ground makes a rising wind
You only need two ideas. Watch each one:
The cloud-top is freezing
A tall storm cloud is warm and sticky down low, but far below freezing up high. Even on a hot day, the very top of the cloud is colder than your freezer.
Hot ground makes air rise
Sun-baked ground heats the air, and warm air shoots upward. That rising column is an updraft — an invisible wind blowing straight up the middle of the cloud.
2Two kinds of updraft
A gentle puff vs a violent blast
Not every storm has the same upward wind. The whole story turns on how strong that updraft is:
The gentle puff
A soft breeze of rising air. An ice pellet drifts down through it and falls out the bottom.
The violent blast
A fierce column of rising air, strong enough to catch a falling pellet and shove it back up.
3Your turn — be the storm's wind
Drag the updraft and feel it push on a pellet
Here's one little ice pellet floating in the cloud. Slide the updraft from a puff to a blast and watch how hard the rising wind pushes back on it — a strong updraft can hold it up high; a weak one lets it sink.
4Now grow a real hailstone
Drop a pellet in and watch it try to grow 🧊
The practice pellet kept the same size. Now let matching pellets collect supercooled droplets that freeze onto them. Compare two updrafts with the same drop supply. The looping path stands for time in the cloud; rings mark growth, not real journey counts. Predict which collects more ice before it falls out.
Guess before you release it
Both pellets have the same supply of supercooled drops. Which pellet will collect more ice before leaving its model cloud?