Hailstone Growth Lab: Understanding Supercell Dynamics

Formation of Hailstones

Hailstones form in severe thunderstorms known as supercells. These storms create strong updrafts that can carry ice crystals and water droplets high into the atmosphere, where they freeze. As these ice particles ascend further, they encounter supercooled water (water below freezing but not yet frozen). When a hailstone embryo is introduced to such an environment, it begins to accrete these supercooled droplets, growing larger as it rises.

The process of growth can switch between dry and wet modes. In the dry mode, the stone grows by colliding with ice crystals, while in the wet mode, it absorbs supercooled water that freezes upon contact.

Governing Principles

The growth of hailstones is governed by several key principles. The Schumann-Ludlam criterion, for instance, states that a hailstone will continue to grow as long as the updraft can support it and there are sufficient supercooled droplets available. This criterion helps predict whether a storm has the potential to produce large hail.

Additionally, the wet-growth limit is crucial in determining when a hailstone transitions from dry growth to wet growth. Beyond this limit, the stone's surface temperature becomes too warm for further freezing of supercooled water, halting its growth.

Real-World Implications

Understanding hailstone formation is vital for meteorologists and climatologists. Large hail can cause significant damage to property and infrastructure, as well as pose a risk to human life. Accurate forecasting of severe storms with large hailstones can help in issuing timely warnings and mitigating potential hazards.

Furthermore, studying hailstone growth provides insights into cloud physics and the broader atmospheric processes that influence weather patterns.

Interactive Learning

The Hailstone Growth Lab offers a unique interactive experience to explore these complex phenomena. By observing the stone's journey through different stages of growth, learners can gain a deeper understanding of how atmospheric conditions affect hail formation.

Through numerical checks and cutaway views, users can see the internal structure of the hailstone at various points in its development, enhancing their comprehension of the physical processes involved.

Frequently asked questions

Try it live

Everything above runs in your browser — open Hailstone Growth Lab: Updraft Accretion, Wet-Growth Limit, Melting and a Layered Cutaway and change the parameters while it is running. Nothing is installed, nothing is uploaded, the whole model lives in one tab.