What Causes a Hail Storm? Science, Risks, and Real-Life Impacts
Hailstorms—also known as a Hail Storm—happen when chunks of ice, called hailstones, fall from the sky during strong thunderstorms. A Hail Storm can cause injuries, damage cars, homes, crops, and even disrupt power; in severe cases, really large hailstones can lead to serious harm. Knowing what a hailstorm is, how a Hail Storm forms, and how to stay safe can make a big difference. This guide covers everything you need to know about hailstorms—from causes to preparation and response to a Hail Storm.
What is a Hail Storm?
A hail storm is a destructive weather phenomenon accompanied by hail, triggered by a strong convective weather system. It typically forms within well-developed cumulonimbus clouds, where intense vertical airflows cause water vapor to condense into ice particles in the cold high-altitude environment. These ice particles continuously collide and merge in the airflows, gradually increasing in size. When their gravity exceeds the lifting force of the air currents, they fall to the ground as hail, thereby forming a hailstorm.
Formation Conditions
Intense Convective Motion: This is the core driving force for hail formation. Warm and humid air currents generated by heated ground keep rising and meet cold air currents at high altitudes, forming a strong vertical air current cycle, which provides sufficient movement space for the growth of ice particles.
Adequate Water Vapor: The atmosphere needs to contain abundant water vapor. As the water vapor rises, it condenses into water droplets, providing the material basis for hail formation.
Appropriate Temperature Stratification: The temperature from the bottom of the cloud to the ground must meet the "cold upper and warm lower" condition. That is, the temperature at high altitudes is low enough (usually below -10℃) to freeze water droplets into ice, while the temperature near the ground is relatively high, preventing the ice particles from completely melting during their fall.
Main Characteristics
Hail Properties: Hail varies greatly in size, with small ones as tiny as mung beans or soybeans, and large ones as big as eggs or even fists. They typically measure over 5 millimeters in diameter, and are mostly spherical, conical, or irregular in shape with a hard texture.
Accompanying Weather: Hailstorms are often accompanied by short-term heavy rainfall, strong winds, and thunderstorms, intensifying the storm’s destructive impact.
Suddenness and Locality: Hailstorms form and develop rapidly, often occurring suddenly, and their impact range is relatively concentrated. The degree of disaster in different areas may vary significantly.
What Kind of Damage Can a Hail Storm Cause?
Hailstorms, due to their suddenness and high intensity, can cause significant damage in multiple areas.
The specific impacts are as follows:
1. Agriculture and Animal Husbandry
Crop Damage: The impact force of falling hailstones can smash the leaves, stems, and fruits of crops, leading to reduced yields or even total crop failure for crops such as wheat, corn, and fruit trees.For example, ripe fruits like apples and grapes, when hit by hailstones, will have holes or damaged skins, losing their commercial value; the leaves of vegetable crops, once smashed, will have their photosynthetic capacity inhibited
Livestock Losses: Poultry and livestock raised outdoors may be injured by hailstones, with young ones being more vulnerable. Meanwhile, pasture grass is destroyed, resulting in a shortage of livestock feed.
2. Infrastructure and Buildings
Building Facilities: House roofs (especially those with tiles or color steel) can be easily pierced or shattered by large hailstones
Public Facilities: Utility poles, street lamps, traffic lights, etc., may be damaged by hailstones or accompanying strong winds, leading to power outages and communication disruptions; road guardrails and traffic signs may also be dented by the impact.
3. Means of Transportation
The bodies of cars, trains, and other vehicles can be dented by hailstones, and window glass is easily broken; if an airplane encounters hailstones at low altitude, its engine or fuselage may be damaged, endangering flight safety.
4. Ecological Environment and Personal Safety
Ecological Damage: Hailstones can injure the branches and leaves of trees, and in severe cases, cause trees to break. At the same time, the melted hailstones falling on the ground may trigger local floods, wash away soil, and cause soil erosion.
Personal Injuries: If people fail to take shelter in time when outdoors, they may be injured on the head or skin by hailstones, and even suffer serious injuries such as bone fractures.
5. Economic and Social Impacts
Industries such as agriculture, construction, and insurance will suffer direct economic losses due to the disaster; post-disaster repair and reconstruction efforts will also consume significant human and material resources, indirectly affecting the normal operation of society.
In conclusion, the damage caused by hailstorms is multi-dimensional and sudden. Advance early warning and proper protective measures (such as reinforcing crop greenhouses, storing vehicles in garages, and taking shelter for people) are key to reducing losses.
How Can You Prepare for a Hail Storm?
The suddenness and destructiveness of hailstorms often catch people off guard. Systematic preparation in advance can minimize the risk of casualties and property damage. In particular, hailstorms may trigger power outages and communication disruptions, making comprehensive planning even more crucial.
Here are detailed steps to help you prepare effectively:
1. Stay Updated with Real-Time Information for Early Warnings
Monitor Professional Channels: In Australia, spring and summer are peak seasons for hailstorms. Check daily weather forecasts issued by the Bureau of Meteorology (BoM) and pay close attention to official alerts such as "Severe Thunderstorm Warning with Hail." You can subscribe to local weather alert SMS via the BoM website, or download its official app "BOM Weather" and enable real-time push notifications to receive critical information—including storm formation times, movement paths, and affected areas—as soon as they become available.
Recognize Warning Signs: Dark gray clouds, strong gusts, or intensifying distant thunder may signal an approaching hailstorm. Stay on high alert if these signs appear.
2. Reinforce Property Comprehensively to Reduce Direct Damage
Secure Outdoor Items: Move loose objects on balconies or in yards (flower pots, clotheslines, grills) indoors to prevent them from becoming projectiles in strong winds. For immovable facilities (air conditioning units, solar panels), cover them with thick canvas or wooden boards and secure them firmly to reduce the impact of hailstones.
Protect Windows and Roofs: If a severe hailstorm (with hail diameters ≥ 2 cm) is forecast, install storm shutters or apply explosion-proof film to windows (to minimize the risk of shattering). For older roofs, temporarily lay waterproof tarps and weigh them down with heavy objects to prevent leaks if hailstones puncture the tiles.
Clear Drainage Systems: Unclog roof gutters and ground drains in advance, removing leaves, sludge, and debris to prevent rainwater from backing up during storms.
3. Protect Vehicles Targetedly to Lower Repair Costs
Daily Parking Planning: Make it a habit to park in garages. If no garage is available, choose covered spots (e.g., residential podiums, shopping mall basements) and avoid open areas, locations under trees (to prevent falling branches), or areas near high-voltage power lines.
Emergency Protection Measures: If an urgent hail warning is issued and the vehicle cannot be moved, cover it with thick quilts or specialized anti-hail car covers (made of wear-resistant and impact-resistant materials). Place wooden boards or foam sheets on the roof to cushion hail impacts.
Responding to Sudden Hail While Driving: If caught in a hailstorm while driving, immediately turn on hazard lights, slow down, and head to the nearest shelter (e.g., gas station awnings, tunnel entrances). Never stop under bridges or billboards. Once parked, close the windows, have all occupants crouch under seats, and protect their heads with clothing until the storm passes.
4. Prepare an Emergency Kit to Cope with Power/Water Outages
Basic Survival Supplies: Stock 3+ days of drinking water (1.5 liters per person per day) and non-perishable food (canned goods, energy bars). Include flashlights (preferably high-lumen models with 3+ sets of spare batteries), hand-crank radios (to receive emergency broadcasts), and lighters or matches.
Medical and Safety Items: Equip a first-aid kit with iodine, bandages, band-aids, painkillers, scissors, and tweezers. For family members with chronic illnesses, store an adequate supply of prescription medications (e.g., blood pressure drugs, insulin).
Power Backup Equipment: A portable power station is essential for handling outages. Choose models with a capacity of 2kWh or more, which can power critical devices like refrigerators, medical equipment, and phones.
If you’re looking for a reliable backup power solution, the EcoFlow DELTA 2 Max Portable Power Stationis undoubtedly an ideal choice. It features an expandable capacity of 2-6kWh, and when paired with X-Boost mode, it can deliver up to 3300W of power—more than enough to keep essential devices like refrigerators, medical equipment, and communication tools running continuously. Even during home repairs caused by power outages, it stably ensures that basic living and emergency needs remain uninterrupted, giving you complete peace of mind throughout the process.
EcoFlow DELTA 2 Max Portable Power Station
5. Establish a Family Emergency Plan to Ensure Coordination
Designate Safe Zones: Identify a "storm shelter" at home, prioritizing windowless basements, bathrooms, or stairwells (as these are sturdier structures). Clear clutter in these areas and store first-aid kits, water, and supplies there.
Create a Communication Plan: Agree on an emergency contact person (preferably someone outside the local area to avoid loss of contact if local networks fail) and memorize each other’s phone numbers. Set meeting points (e.g., community squares, nearby supermarkets) in case family members are separated during the storm.
Drills and Training: Conduct 1-2 family emergency drills annually. Teach elderly members and children how to move quickly to safe zones and use first-aid kits, ensuring calm responses during emergencies.
By following these steps, you can effectively protect your family and property during a hailstorm while enhancing resilience against all types of extreme weather. Remember: the more thorough your preparation, the more control you’ll have when disaster strikes.
What Should You Do During a Hail Storm?
Stay calm and follow these tips based on where you are:
In a Car: Pull over safely to a covered spot like a garage or awning. Avoid stopping under bridges. Stay inside, keep away from windows, and protect your eyes with clothing. Shield children’s eyes too.
Indoors: Stay inside a sturdy building, away from windows and skylights. Stay in interior rooms or basements if possible. Avoid using plugged-in electrical devices to reduce lightning risk.
Outside: Find shelter immediately—inside a building or vehicle is best. If not available, protect your head and body with anything handy. Avoid low-lying flood-prone areas and don’t shelter under trees.
Wait until the storm passes completely before going outside and watch for hazards like broken glass or downed power lines.
What to Do After a Hail Storm?
After a hailstorm passes, your first priority should always be safety. Once you’re sure everyone—including pets—is safe, it’s time to inspect your property carefully for any damage.
1. Assess Immediate Safety Hazards
Look out for broken windows, fallen tree branches, flooded areas, downed power lines, and damaged structures. Don’t go near anything that looks unsafe.
2. Inspect Your Property for Damage
From the ground, check your roof for dents, missing granules on shingles, or discoloration. Examine gutters and downspouts for dents or blockages. Look over your siding and windows for cracks or holes. Don’t forget to check outdoor structures like fences and sheds, as well as your vehicles for dents or broken glass.
3. Document Everything
Take clear photos and videos of all the damage from multiple angles. This will be crucial for insurance claims later on. Record the date and time of the storm to support your case.
4. Contact Professionals if Needed
Some damage might not be obvious. Hiring a trusted roofing contractor for a thorough inspection can save you from bigger issues down the road. Beware of door-to-door storm chasers and always check credentials.
5. Understand and File Your Insurance Claim
Review your insurance policy carefully to know what’s covered, including deductibles and claim deadlines. File your claim promptly and keep detailed records of all communications with your insurer.
6. Temporary Repairs
While waiting for insurance approval, protect your home by covering damaged roofs with tarps or sealing minor cracks with silicone to prevent water damage.
7. Schedule Permanent Repairs
Once approved, work with reputable contractors to restore your home. Using impact-resistant materials can help protect against future hailstorms.
8. Follow Up and Plan Ahead
Keep in touch with your insurance adjuster, negotiate if needed, and after repairs, consider upgrades like Class 4 impact-rated roofing to strengthen your home against future hail damage.
9. Stay Powered During Recovery
After a hailstorm, if power has not yet been restored, portable power stations remain a critical source of household electricity—they prevent recovery work from being disrupted or daily life from descending into chaos due to power outages, providing reliable energy support throughout the post-disaster reconstruction process. This underscores the importance of building a home battery backup system in responding to extreme weather events.
Taking these steps can help you recover faster and minimize the risk of further damage after a hailstorm.
Conclusion
Hail storms can strike suddenly and cause significant damage to property, vehicles, and even pose risks to personal safety. Knowing how to prepare before a storm, what to do during, and how to respond afterward can make all the difference in protecting yourself and minimizing loss. By staying informed, acting quickly, and working with trusted professionals, you can recover more effectively and safeguard your home against future hailstorms. Remember, preparedness is your best defense when nature unleashes its icy fury.
FAQs
What is hail from a storm?
Hail from a storm refers to solid ice pellets that form inside strong thunderstorms. During these storms, powerful updrafts carry raindrops high into cold parts of the atmosphere, where they freeze and grow into hailstones. When these ice balls become too heavy for the updrafts to hold, they fall to the ground as hail. Hail can vary in size, from small pellets to large stones capable of causing significant damage to property and vehicles.
What was the worst storm in Australia?
One of the worst storms in Australia’s history was the Brisbane hailstorm in November 2014. This severe storm produced hailstones up to 9 centimeters (about 3.5 inches) in diameter, causing widespread damage to homes, vehicles, and infrastructure. The storm resulted in thousands of insurance claims worth hundreds of millions of dollars. It also led to significant power outages and disruptions across Queensland, highlighting the destructive potential of Australian hailstorms.
What is the biggest hailstone ever recorded?
The heaviest hailstone ever documented weighed 2.25 pounds (1.02 kg) and fell in the Gopalganj district of Bangladesh on April 14, 1986. Meanwhile, the hailstone with the largest officially measured diameter—7.9 inches (20 cm)—was recorded in Vivian, South Dakota, on July 23, 2010. Although the heaviest hailstone was found in Bangladesh, the South Dakota hailstone holds the record for both the greatest diameter and circumference. According to USA Today, this enormous hailstone was roughly the size of a volleyball.
Does hail hurt if it hits you?
Yes, hail can definitely hurt if it hits you, especially if the hailstones are large. Small hail might cause only mild discomfort or bruises, but larger hailstones—like those the size of golf balls or bigger—can cause serious injuries such as cuts, bruises, or even concussions. In extreme cases, very large hailstones have been known to cause more severe injuries or even be fatal. That’s why it’s important to seek shelter immediately during a hailstorm to protect yourself from potential harm.