A flight instructor explains that hail forms inside a mature thunderstorm through a specific process. Which statement best describes how large hailstones develop?
- ASupercooled water droplets are repeatedly carried up and down within strong updrafts and downdrafts, accumulating layers of ice
- BHail forms only in stratus clouds where temperatures remain below freezing at all altitudes
- CIce crystals fall directly from the anvil and freeze instantly without growth
- DWarm rain droplets freeze on contact with the ground during winter storms
Show answer & explanationAnswer & explanation
Correct answer: A. Supercooled water droplets are repeatedly carried up and down within strong updrafts and downdrafts, accumulating layers of ice
Hail forms when supercooled water droplets are carried repeatedly through the strong updrafts and downdrafts of a mature thunderstorm, accumulating successive layers of ice each time they pass through regions of supercooled water. Stronger updrafts allow more cycles and larger hailstones before they become too heavy to be supported and fall to the ground.
Why the other options are wrong
- B. Hail requires strong convective updrafts found in cumulonimbus clouds, not stable stratus clouds.
- C. Hail growth requires repeated cycling through the cloud, not instant freezing during a single fall.
- D. Hail forms aloft in convective clouds, not from rain freezing at the surface.
Hail Formation
A process in which supercooled water droplets are carried repeatedly through updrafts and downdrafts in a thunderstorm, building up layers of ice.
- Requires strong, sustained updrafts found in cumulonimbus clouds
- Layers of ice build with each pass through supercooled water regions
- Hail falls when it becomes too heavy for the updraft to support
Memory trick: Hail is a snowball rolled up and down inside a storm's elevator until it's too heavy to hold