Strange Weather Phenomena • Severe Thunderstorms • Giant Hail
Hail starts as a tiny frozen particle inside a thunderstorm. Under the right conditions, an updraft can keep recycling that particle through supercooled water until it grows from pea-sized ice into something closer to a baseball, grapefruit or — in the most extreme cases — a chunk of atmospheric masonry falling at highway speed.
How does hail form, why do some storms produce baseball- or grapefruit-sized stones, and what makes giant hail so destructive? This guide explains hailstone formation, supercooled water, hail embryos, wet and dry growth, giant-hail production in supercells, hail radar signatures, hail accumulation, damage, forecasting and record-breaking hailstones.
Hail is precipitation made of balls or irregular lumps of ice that develop inside powerful convective clouds. Unlike sleet or freezing rain, hail grows inside a thunderstorm through repeated collisions between an ice embryo and supercooled liquid-water droplets. The stronger and more persistent the updraft, the greater the chance that hailstones can remain aloft long enough to become large — and sometimes enormous.
Giant Hail: Quick Facts
- Hail forms inside strong thunderstorm updrafts.
- Most hail begins around a small hail embryo such as frozen droplets, graupel or small ice particles.
- Hail grows mainly by collecting supercooled liquid water.
- Supercooled water remains liquid below 0°C until it freezes onto an ice particle.
- Hailstones can show alternating clear and cloudy ice layers.
- Dry growth tends to produce cloudy ice.
- Wet growth can produce clearer, denser ice.
- Large hail requires strong and persistent updrafts.
- Supercells are among the most efficient giant-hail producers.
- A storm does not need to produce a tornado to produce giant hail.
- Large hail can exceed baseball size.
- Hailstones are rarely perfect spheres.
- Large hail can damage roofs, crops, vehicles, solar panels, aircraft and power infrastructure.
- Hail can accumulate deeply enough to cover roads like snow.
- Large hail can produce distinctive radar signatures, including a three-body scatter spike.
- Radar-estimated hail size is not the same as a measured hailstone.
What Is Hail?
Hail is solid precipitation consisting of individual balls or irregular pieces of ice that form inside deep convective thunderstorms.
Hailstones can range from tiny pellets to enormous pieces of ice several centimeters across.
The defining process is growth inside a thunderstorm updraft.
Hail should not be confused with:
- sleet, which forms when melted snow or rain refreezes before reaching the ground;
- graupel, which consists of soft, heavily rimed snow particles;
- freezing rain, which freezes after reaching cold surfaces;
- snow pellets, which develop through different microphysical pathways.
How Does Hail Form?
Hail formation requires a thunderstorm containing:
- a sufficiently strong updraft;
- subfreezing temperatures aloft;
- supercooled liquid water;
- ice particles that can act as hail embryos.
The basic growth sequence is:
- a small ice particle forms inside the storm;
- the updraft carries it through supercooled liquid-water droplets;
- those droplets collide with the particle and freeze;
- the hailstone gains mass;
- storm airflow may recycle or redirect it through additional growth regions;
- eventually the hailstone becomes too heavy for the updraft or exits the strongest rising air;
- it falls toward the ground.
Giant hail requires this process to continue long enough for the stone to accumulate a remarkable amount of ice.
Hail Embryos: Where Every Hailstone Begins
A hailstone does not begin as a giant ball of ice.
It grows around a small initial particle known as a hail embryo.
Potential hail embryos include:
- frozen cloud droplets;
- graupel;
- small ice crystals;
- small frozen raindrops;
- previously formed tiny hailstones.
The availability and distribution of hail embryos influence how many stones compete for the same supply of supercooled water.
Many Embryos vs Few Embryos
If a storm contains many embryos, available liquid water may be divided among numerous stones.
If fewer embryos enter an extremely water-rich updraft, individual stones may have more opportunity to grow very large.
This is one reason giant-hail production cannot be predicted from updraft strength alone.
Supercooled Liquid Water: The Raw Material for Hail
One of the most important ingredients in hail growth is supercooled liquid water.
These are liquid droplets existing at temperatures below 0°C.
When a hail embryo collides with a supercooled droplet, the droplet can freeze onto the hailstone.
Repeated collisions allow the stone to grow.
Why Doesn’t All Water Freeze Immediately?
Tiny cloud droplets can remain liquid well below the normal freezing point when suitable ice-nucleating particles are absent.
Powerful convective clouds can therefore contain large volumes of liquid water in subfreezing regions.
This supercooled water becomes fuel for hail growth.
How Hailstones Grow
Hail growth depends on the interaction between:
- hailstone trajectory;
- updraft speed;
- liquid-water content;
- temperature;
- collision efficiency;
- time spent inside the hail-growth zone.
Large stones generally require prolonged exposure to strong updraft regions containing abundant supercooled water.
Does a Hailstone Really Go Up and Down Repeatedly?
The popular textbook illustration showing a hailstone making many neat vertical loops through a thunderstorm is an oversimplification.
Real hail trajectories can be much more complex.
Stones may:
- spiral through portions of a rotating updraft;
- move horizontally within storm-relative airflow;
- enter and leave strong growth regions;
- be recycled through portions of the storm;
- grow substantially during one extended pass through favorable conditions.
Wet Growth vs Dry Growth
Hailstone ice can develop under different freezing regimes.
Dry Growth
During dry growth, supercooled droplets freeze rapidly when they hit the hailstone.
Air bubbles can become trapped inside the ice, creating a cloudy or opaque appearance.
Wet Growth
During wet growth, droplets collide with the hailstone faster than all the liquid water can immediately freeze.
A thin liquid layer can temporarily exist on the hailstone surface.
Slower freezing allows air bubbles to escape more efficiently, producing clearer and often denser ice.
Why This Matters
Alternation between wet- and dry-growth conditions can produce the layered internal structure visible when a large hailstone is cut open.
Why Do Hailstones Have Layers?
Large hailstones often contain concentric or irregular layers of:
- clear ice;
- cloudy ice;
- bubbles;
- different crystal textures.
These layers record changing conditions during growth.
A hailstone may encounter:
- different temperatures;
- different liquid-water concentrations;
- different freezing rates;
- different parts of the updraft.
How Does Giant Hail Form?
Giant hail requires an unusual combination of powerful storm dynamics and favorable cloud microphysics.
The most important ingredients include:
- exceptionally strong updrafts;
- large amounts of supercooled liquid water;
- deep hail-growth regions;
- sufficient time inside favorable growth conditions;
- storm organization that prevents premature fallout;
- favorable trajectories through the updraft;
- limited competition from excessive numbers of hail embryos.
Updraft Strength
Large hailstones require powerful rising air to offset their weight.
As the stone grows, it becomes increasingly difficult for the updraft to keep it suspended.
Liquid-Water Content
A strong updraft is not enough if the storm lacks sufficient supercooled liquid water.
Giant hail requires both dynamic support and abundant material to freeze onto the growing stone.
Residence Time
Hailstones must spend enough time inside the storm’s favorable growth region.
A powerful but short-lived updraft can produce severe hail, while a persistent organized updraft may allow stones to become much larger.
Why Do Supercells Produce Giant Hail?
Supercells are among the most efficient giant-hail-producing thunderstorms because they combine powerful updrafts with exceptional storm organization.
Strong vertical wind shear separates the rotating updraft from much of the precipitation and downdraft air.
This allows the updraft to remain:
- strong;
- persistent;
- spatially organized;
- rich in supercooled liquid water.
Hailstones can therefore follow trajectories through the storm that keep them inside favorable growth zones for longer periods.
Rotation Does Not Directly Create Giant Hail
Rotation itself does not freeze extra ice onto the stone.
Its importance is indirect: the rotating supercell structure helps sustain and organize the intense updraft environment required for extreme hail growth.
Hail Size Categories
Hail is often described using familiar objects because most people do not carry calipers into a severe thunderstorm.
| Approximate Diameter | Common Comparison | Potential Impact |
|---|---|---|
| 6 mm / 0.25 in | Pea | Usually minor |
| 13 mm / 0.5 in | Marble | Minor crop or vegetation damage possible |
| 19 mm / 0.75 in | Penny | Increasing damage potential |
| 25 mm / 1 in | Quarter | Common U.S. severe-hail threshold |
| 32 mm / 1.25 in | Half-dollar | Vehicle and roof damage possible |
| 44 mm / 1.75 in | Golf ball | Significant damage |
| 51 mm / 2 in | Hen egg | Severe roof and vehicle damage |
| 64 mm / 2.5 in | Tennis ball | Potentially destructive |
| 70 mm / 2.75 in | Baseball | Major structural and vehicle damage |
| 102 mm / 4 in | Softball | Extremely destructive |
| 114–127+ mm / 4.5–5+ in | Grapefruit or larger | Extreme giant-hail territory |
Why Are Giant Hailstones So Irregular?
Hailstones are not always spherical.
Large stones can develop:
- lobes;
- spikes;
- ridges;
- flattened surfaces;
- uneven layers;
- clusters of smaller stones frozen together.
Irregular shapes can result from:
- uneven water collection;
- changing airflow around the stone;
- collisions;
- partial melting;
- wet-growth processes;
- aggregation of smaller ice particles.
Spiky Hailstones
Large hailstones sometimes develop dramatic spikes or protrusions when ice growth becomes strongly uneven.
These shapes can make impact damage worse because force becomes concentrated onto smaller contact areas.
How Fast Does Hail Fall?
A hailstone accelerates downward until aerodynamic drag roughly balances gravitational force.
This is its approximate terminal velocity.
Falling speed depends on:
- hailstone diameter;
- mass;
- density;
- shape;
- air density;
- melting;
- vertical wind.
Larger and denser stones generally fall faster than small hail.
Strong storm downdrafts can add downward momentum, while powerful updrafts can temporarily slow or reverse descent.
Why Giant Hail Is So Destructive
Impact energy rises rapidly as hailstone mass and speed increase.
This is why doubling hail diameter can produce much more than double the damage.
Hail Accumulation: When Ice Covers the Ground Like Snow
Hailstorms can occasionally produce such enormous quantities of ice that streets, fields and roofs become buried beneath deep accumulations.
Hail accumulation may:
- cover roads;
- block drainage systems;
- accumulate in low terrain;
- form deep drifts;
- damage crops;
- increase roof loading;
- contribute to localized flooding.
Hail Drifts
Flowing water can transport hailstones into low areas, producing accumulations far deeper than the amount that originally fell at one point.
Hail Fog
Thick hail deposits can rapidly cool humid air near the ground and occasionally create shallow fog over the ice-covered surface.
How Radar Detects Hail
Weather radar cannot directly hold a hailstone in its hand and measure it with a ruler.
Instead, meteorologists infer hail using combinations of:
- radar reflectivity;
- vertical storm structure;
- dual-polarization variables;
- environmental temperature profiles;
- hail-detection algorithms;
- surface observations.
High Reflectivity
Hail can produce very strong radar reflectivity because large ice particles strongly scatter radar energy.
High reflectivity alone, however, cannot determine exact hail size.
Dual-Polarization Radar
Dual-polarization radar examines how returned energy behaves in horizontal and vertical orientations.
These measurements can help distinguish:
- heavy rain;
- mixed rain and hail;
- large hail;
- other hydrometeor types.
Vertically Integrated Hail Indicators
Operational hail algorithms combine radar and environmental data to estimate hail probability and potential size.
These products are extremely useful but remain estimates rather than direct ground measurements.
Three-Body Scatter Spike: A Radar Signature of Extreme Hail
One of the most dramatic radar clues to very large hail is the Three-Body Scatter Spike (TBSS).
It appears as an artificial extension of radar reflectivity behind a hail core, away from the radar.
The effect occurs when radar energy follows a multiple-scattering path involving:
- the radar beam reaching large hail;
- energy scattering toward the ground;
- the ground reflecting part of that energy back toward the hail;
- the hail scattering it back to the radar.
Because the signal has traveled a longer path, the radar places the returned energy farther away than the real hail core.
How Meteorologists Forecast Giant Hail
Giant-hail forecasting requires more than simply finding high CAPE.
Forecasters evaluate the entire environment controlling updraft strength, freezing processes and storm organization.
Instability and CAPE
Strong instability can support powerful updrafts capable of suspending large stones.
However, high CAPE does not guarantee giant hail.
Mid-Level Lapse Rates
Steep temperature decreases with height can promote strong buoyancy and intense updraft acceleration.
Freezing Level
The altitude of the freezing level influences:
- where hail growth occurs;
- how far hail must fall through above-freezing air;
- how much melting occurs before impact.
Wet-Bulb Zero Height
The wet-bulb zero level is useful for estimating how much melting hail may experience while descending toward the surface.
Deep-Layer Wind Shear
Strong shear helps organize storms and separate updrafts from precipitation.
This is one reason giant hail is strongly associated with supercells.
Storm Mode
Discrete supercells often provide more favorable giant-hail environments than densely packed storms competing for unstable air.
Supercell Type
Classic and LP supercells are famous giant-hail producers, but HP supercells can also produce enormous stones.
Radar Trends
Once storms develop, forecasters watch:
- rapid reflectivity increases;
- strong updraft signatures;
- WER/BWER development;
- hail cores;
- dual-pol signatures;
- three-body scatter spikes.
How Giant Hail Causes Damage
Hail damage depends on much more than diameter alone.
Important factors include:
- hailstone mass;
- density;
- shape;
- impact speed;
- wind speed;
- impact angle;
- duration of the hailstorm;
- material being struck.
Vehicles
Large hail can:
- shatter windshields;
- dent metal bodywork;
- break lights;
- damage sunroofs;
- destroy exposed vehicles during extreme storms.
Roofs and Buildings
Hail can crack roofing materials, puncture membranes, break skylights and damage siding.
Some damage is not immediately visible and can later contribute to water leakage.
Agriculture
Hail can destroy:
- fruit;
- grapes;
- grain crops;
- corn;
- vegetables;
- young trees;
- greenhouses.
A severe hailstorm lasting only minutes can erase an entire growing season.
Aircraft
Aircraft encountering severe hail can suffer:
- damaged noses;
- cracked windshields;
- dented wings;
- engine damage;
- damaged sensors and leading edges.
Solar Panels
Modern solar modules are tested against hail impact, but exceptionally large hail can exceed design tolerances and crack glass or underlying cells.
Largest and Heaviest Hailstones
Hail records are surprisingly complicated.
Different records may refer to:
- maximum diameter;
- maximum circumference;
- maximum weight;
- national records;
- officially verified records;
- credible but incompletely documented stones.
A hailstone can be the widest without being the heaviest.
Irregular shape, density and melting after impact complicate comparisons.
Why Verification Matters
Giant hail begins melting immediately after reaching the ground.
Accurate documentation therefore requires:
- rapid measurement;
- photographs with scale;
- maximum-diameter measurement;
- circumference where useful;
- weight;
- location;
- time;
- credible witnesses;
- meteorological verification.
Historic Giant-Hail Events
This section should remain selective and focus on benchmark events that demonstrate hail physics, extreme size, major damage or unusual accumulation.
Vivian, South Dakota — July 23, 2010
The Vivian hailstone became one of the most famous verified giant-hail specimens in the United States and remains an important reference point in discussions of extreme hail size and weight.
Central United States Giant-Hail Supercells
The Great Plains repeatedly produce baseball-, softball- and occasionally larger hail because powerful instability and wind shear frequently combine to create long-lived supercells.
Canadian Prairie Giant Hail
Alberta and surrounding regions are well known for severe hailstorms capable of causing major agricultural, vehicle and property losses.
European Giant-Hail Outbreaks
Northern Italy, France, Switzerland, Germany, Austria and parts of the Balkans can experience extremely intense warm-season supercells producing destructive giant hail.
Argentina and South America
Argentina and neighboring regions contain some of the world’s most favorable environments for giant hail, including exceptionally intense deep convection east of the Andes.
Where Does Giant Hail Occur?
Giant hail can occur on several continents wherever powerful convective updrafts and favorable storm organization develop.
Great Plains, United States
The central United States combines:
- Gulf moisture;
- steep lapse rates;
- strong instability;
- drylines and frontal boundaries;
- strong vertical wind shear.
These ingredients regularly support hail-producing supercells.
Canadian Prairies
Alberta and neighboring regions frequently experience severe hail because moist low-level air can interact with dry, cool air aloft and strong storm-scale forcing.
South America
The region east of the Andes, including parts of Argentina, Paraguay, Uruguay and southern Brazil, supports extremely intense convection and some of Earth’s most impressive giant-hail storms.
Europe
Severe hail occurs across:
- northern Italy;
- France;
- Switzerland;
- Germany;
- Austria;
- Slovenia;
- Croatia;
- the Balkans;
- parts of Eastern Europe.
Australia
Eastern Australia, including Queensland and New South Wales, experiences severe supercells capable of producing damaging giant hail.
Asia
Parts of China, India, Pakistan, Bangladesh and the Middle East can also experience extreme hailstorms under favorable convective conditions.
Climate Change and Giant Hail
Hail is particularly difficult to study over long periods because the phenomenon depends on several atmospheric ingredients that may change differently.
Potentially Favorable Changes
Warmer low-level air can increase:
- atmospheric moisture;
- instability in some environments;
- potential thunderstorm updraft strength.
Potentially Limiting Changes
Hail reaching the ground must also survive descent through above-freezing air.
Higher melting levels can cause smaller hailstones to melt more efficiently before reaching the surface.
Wind Shear
Giant hail also depends heavily on storm organization and vertical wind shear.
Long-term changes in shear vary geographically and seasonally.
Why Hail Trends Are Hard to Measure
Observational records are affected by:
- population density;
- storm-reporting practices;
- radar-network improvements;
- changes in insurance claims;
- poor observation over rural areas;
- inconsistent historic hail-size estimates.
Hail Myths and Misconceptions
| Myth | Reality |
|---|---|
| Hail is frozen rain. | Hail grows inside thunderstorm updrafts by collecting supercooled water. |
| Every hailstone repeatedly travels straight up and down through the storm. | Real hail trajectories are three-dimensional and can be much more complex. |
| Every ice layer equals one complete trip through the thunderstorm. | Layers record changing growth conditions, not necessarily complete vertical cycles. |
| Only tornado-producing storms create giant hail. | Many non-tornadic supercells produce enormous hail. |
| Rotation directly makes hailstones larger. | Rotation helps maintain the organized updraft environment; hail grows through collisions with supercooled water. |
| Very deep hail accumulation means every hailstone was giant. | Enormous accumulations can result from vast quantities of small or moderate hail. |
| Radar measures hail size directly. | Radar estimates hail probability and potential size using indirect signatures. |
| A three-body scatter spike is a real precipitation plume behind the storm. | It is a radar artifact produced by multiple scattering involving hail and the ground. |
Which Legacy Articles Should Redirect to Giant Hail Explained?
Redirect a legacy article here when hail itself is the dominant scientific or event topic.
Redirect to Giant Hail Explained when the article focuses on:
- giant hailstones;
- baseball-sized hail;
- softball-sized hail;
- grapefruit-sized hail;
- hail records;
- record hailstones;
- hailstone weight;
- hailstone diameter;
- hail accumulation;
- hail drifts;
- hail-covered roads;
- hail damage to vehicles;
- hail damage to homes;
- hail crop damage;
- hail damage to aircraft;
- extreme hailstorms;
- hail radar signatures;
- three-body scatter spikes;
- hail formation or hailstone growth.
Redirect Elsewhere When Another Hazard Dominates
| Dominant Topic | Best Destination |
|---|---|
| General severe-thunderstorm outbreak with multiple hazards |
Severe Thunderstorms Explained |
| Supercell anatomy, mesocyclone or rotating updraft |
Supercell Structure Explained |
| Tornado damage or tornado outbreak |
Tornadoes Explained |
| Microburst, downburst, derecho or destructive wind |
Extreme Wind Phenomena Explained |
| Lightning science, strikes or electrical records |
Lightning Explained |
| Flash flooding caused by thunderstorms |
Flash Floods Explained |
Giant Hail Glossary
| Term | Meaning |
|---|---|
| Hail | Solid precipitation grown inside a convective thunderstorm. |
| Hail Embryo | A small initial ice particle around which a hailstone grows. |
| Supercooled Water | Liquid water existing below 0°C. |
| Riming | Freezing of supercooled liquid droplets onto an ice particle. |
| Dry Growth | Rapid freezing that commonly traps air and produces opaque ice. |
| Wet Growth | Growth where water does not immediately freeze completely, often producing clearer ice. |
| Hail Core | The portion of a thunderstorm containing high concentrations of hail. |
| Hail Swath | A corridor where hail falls along a storm track. |
| Hail Accumulation | Hail collecting deeply enough to cover the ground. |
| TBSS | Three-Body Scatter Spike, a radar artifact associated with very large hail. |
| Freezing Level | Altitude where atmospheric temperature reaches approximately 0°C. |
| Wet-Bulb Zero | Altitude where the wet-bulb temperature reaches 0°C, useful for assessing hail melting. |
| Terminal Velocity | Approximate falling speed reached when aerodynamic drag balances gravitational acceleration. |
Sources and Editorial Methodology
Hail formation, record claims, radar interpretation and historic events should be checked against operational meteorology, official storm reports and peer-reviewed atmospheric science.
Preferred Primary Sources
-
NOAA National Severe Storms Laboratory
-
NOAA National Weather Service
-
NOAA Storm Prediction Center
- European Severe Storms Laboratory
- Environment and Climate Change Canada
- National meteorological agencies
- Official storm-report databases
- Peer-reviewed hail and cloud-microphysics research
StrangeSounds Editorial Rules
- Use measured hail diameter whenever available.
- Separate diameter, circumference and weight records.
- Identify whether a record is officially verified.
- Do not use forced-perspective photographs as size evidence.
- Remember that hail melts immediately after reaching the ground.
- Do not describe every severe hailstorm as record-breaking.
- Separate giant-hail events from general severe-thunderstorm outbreaks.
- Keep full supercell anatomy within Supercell Structure Explained.
- Keep tornado science within Tornadoes Explained.
- Keep microbursts and downbursts within Extreme Wind Phenomena Explained.
- Distinguish radar-estimated hail size from direct measurements.
- Use benchmark events as case studies and redirect routine legacy hail reports here.
Frequently Asked Questions About Giant Hail
What is hail?
Hail is solid precipitation made of balls or irregular pieces of ice that grow inside strong convective thunderstorms.
How does hail form?
Hail forms when ice embryos inside a thunderstorm collide with supercooled liquid-water droplets that freeze onto them. Continued growth can eventually produce large hailstones.
Is hail just frozen rain?
No. Hail grows inside thunderstorm updrafts through repeated interactions with supercooled water. Frozen rain and sleet form through different processes.
What is a hail embryo?
A hail embryo is the initial small ice particle around which a hailstone grows. It can begin as graupel, frozen droplets or another small ice particle.
What is supercooled liquid water?
Supercooled water is liquid water that remains unfrozen at temperatures below 0°C. These droplets freeze onto hail embryos and provide much of the mass required for hail growth.
Why do hailstones have layers?
Layers form as hailstones move through regions with different temperatures, liquid-water contents and freezing conditions. Clear and cloudy layers often reflect differences between wet and dry growth.
Does every hail layer mean the stone went up and down once?
No. Hail trajectories are three-dimensional and complex. Layers represent changing growth conditions rather than one complete vertical trip per layer.
What is wet hail growth?
Wet growth occurs when supercooled water reaches a hailstone faster than all of it can immediately freeze, leaving a temporary liquid layer that can produce clearer ice.
What is dry hail growth?
Dry growth occurs when droplets freeze rapidly on contact, trapping air bubbles and commonly producing cloudier ice.
Why do supercells produce giant hail?
Supercells contain powerful, persistent and highly organized updrafts that can keep growing hailstones inside favorable supercooled-water regions for extended periods.
Does a supercell need to produce a tornado to make giant hail?
No. Many non-tornadic supercells produce extremely large hail.
What size hail is considered severe?
In the United States, hail at least 1 inch in diameter generally meets the severe-thunderstorm hail criterion.
How large can hailstones become?
Extreme thunderstorms can produce hailstones larger than baseballs and softballs, with rare documented stones reaching grapefruit-like dimensions.
Why are giant hailstones irregularly shaped?
Uneven water collection, changing airflow, collisions, partial melting and aggregation can create lobes, ridges and spikes instead of perfect spheres.
How fast does hail fall?
Hail speed depends on stone size, shape, density, air density and vertical wind. Large dense hailstones can fall much faster than small hail.
Can hail cover the ground like snow?
Yes. Intense hailstorms can produce deep accumulations and hail drifts capable of covering roads, blocking drainage and creating ice-covered landscapes.
What is a hail swath?
A hail swath is the corridor along a storm track where hail reaches the ground.
What is a three-body scatter spike?
A three-body scatter spike is a radar artifact caused by multiple scattering between the radar, large hail and the ground. It can indicate a storm containing very large hail.
Can radar measure hailstone size exactly?
No. Radar can estimate hail probability and potential hail size, but direct measurements on the ground are required to verify individual stones.
What atmospheric conditions favor giant hail?
Giant hail is favored by strong persistent updrafts, high instability, steep lapse rates, abundant supercooled water, favorable freezing levels, strong deep-layer wind shear and organized storm modes such as supercells.
Can hail fall during hot weather?
Yes. Hail forms high inside thunderstorms where temperatures are below freezing even when surface temperatures are very warm.
Why does hail sometimes melt before reaching the ground?
Hailstones descending through a deep layer of warm air can partially or completely melt before reaching the surface.
Where is giant hail most common?
Giant hail is especially common in parts of the Great Plains, Canadian Prairies, South America, Europe and Australia where strong instability and organized severe thunderstorms occur.
Can hail damage aircraft?
Yes. Severe hail can damage aircraft noses, windshields, engines, wings, sensors and leading edges.
Can hail break solar panels?
Yes. Solar panels are designed and tested for hail impacts, but exceptionally large hailstones can exceed design tolerances and cause cracking or structural damage.
Where should old hail articles redirect?
Articles mainly about giant hail, hail records, hail accumulation, hail damage, hailstone size or hail formation should redirect to Giant Hail Explained.
Where should tornado-and-hail outbreak articles redirect?
Redirect to Giant Hail Explained when hail is clearly the main subject. If the article primarily concerns a tornado outbreak, use Tornadoes Explained; if it covers several severe hazards equally, use Severe Thunderstorms Explained.
Where should supercell articles that mention hail redirect?
If the article mainly explains rotating supercell structure, mesocyclones or storm dynamics, redirect to Supercell Structure Explained. If the dominant subject is the hail produced by the storm, redirect here.
