Planning for Emergencies: Hail (Third of a Series)

People are the most important part of any business. When preparing or reviewing your business plan regularly, make sure you have emergency plans also in place for you, your people and your business.

In the third part of our series, we will continue to give you information on protecting yourself and others for different situations. The topic of our third blog covers a threat that accompanies other forms of severe weather, such as severe thunderstorms and tornadoes. That threat is hail.

Severe Weather Awareness: Hailstorms

On the afternoon of June 3, 2014, a line of severe thunderstorms hit eastern Nebraska and western Iowa, accompanied by hail the size of golf and tennis balls. One of the hardest hit cities was Blair, Nebraska in Washington County, 25 miles north of Omaha. A number of downtown businesses were hit hard; a dozen people were injured outside the city’s Walmart. Hardest hit was Woodhouse Ford, with an estimated $162 million in total damage to more than 4,500 cars, ranging from dents in the hoods and roofs to bashed-in front and rear windshields and side windows. A number of houses had their siding and roofs shredded as though by heavy machine gun fire.

On 10 April 2001, a hailstorm traveled over Interstate 70 from eastern Kansas to southeastern Illinois, hammering the St. Louis area and producing a record $2.4 billion in damage, adjusted for inflation to 2010 dollars. The National Oceanographic and Atmospheric Administration (NOAA) estimates that hailstorms cause, on average, $1 billion each year in property damage.

The number of insurance claims for hail damage has climbed steadily at the beginning of this decade. According to the National Insurance Crime Bureau, 467,202 hail damage claims were filed in 2010. This number increased to 689,267 in 2011, a 48 percent increase, and to 861,597 in 2012, a 25 percent increase over the preceding year but an 84 percent increase from two years prior,

What is Hail and How Does It Form?

Hail is, essentially, frozen rain. Rain occurs when droplets of water inside clouds become too heavy to stay aloft or when ice crystals/snowflakes fall into warmer air that melts them back into liquid form. However, when storms have severe updrafts, the wind intercepts the ice crystals before they can melt and sends them back up to the top of the cloud, where more moisture condenses over them and freezes, making the ice pellet larger. The stronger the updraft, the more times the ice pellets are caught and blown upward to be coated with still more layers of ice.

Depending on how high in the cloud the ice pellet is blown, the new layer may either be a slowly frozen clear layer without air bubbles or a quick-frozen cloudy later pockmarked with bubbles of air that didn’t have time to escape. It’s possible to determine how many times the hailstone was caught up before finally falling to the ground by cutting it open and counting the rings formed by the layers of ice.

This process repeats until the ice is too heavy to be carried back up into the cloud or until a downdraft shunts it earthward. In either case, it falls as hail. The stones are so large and heavy they don’t have time to melt back into rain.

Hail generally forms in paths called swaths, which can range from a radius of a few acres to areas 10 miles wide and 100 miles long. In these swaths, hail can fall so densely that it forms drifts like snow and, like heavy snowfall, a snowplow is necessary to remove it.

When Is Hail Most Likely to Form?

In the United States, hail forms principally during the months of April through July, with May and June the two months where hail falls the most: in 2013, 1,376 hailstorms were reported in the U.S. in May and 1,145 in June. However, hail can fall outside this period as well: on 23 March, 2007, the Clovis-Roswell-Logan area in New Mexico was hit with a combination of tornadoes and hail that did $16.5 million in reported damage, while on 29 September, 2014 the Metropolitan Denver area was hit with a hailstorm that did $213.3 million in damage.

What Kinds of Damage Does Hail Cause?

Hail can cause billions of dollars in damage to buildings and vehicles. According to Farmers Insurance Company, hail accounts for 86 percent of damage claims for cars in Nebraska and 57 percent of auto damage claims in Iowa. Hail damage is the reason for 65 percent of home damage claims in Nebraska and 32 percent of Iowa home damage claims. Farmers are particularly vulnerable to hail damage, not just for their homes, barns and silos, but also their crops. Pea-sized hail can rip through a vegetable garden or field of grain, while a tennis ball-sized hailstone (diameter 2.5 inches) can hit the ground, a roof or car at speeds over 100 mph.

What Types and Sizes of Hail Are There?

Hail is only one form of frozen precipitation; snow is another. In between are two other kinds: sleet and graupel.

Sleet is what ice pellets are called when they reach the ground without being caught up by the wind to have more layers added. They are smaller than hailstones and often translucent. They are hard enough to bounce upon hitting the ground. (In the United Kingdom, Ireland and most countries that belong to the British Commonwealth of Nations, sleet also refers to a mixture of rain and snow.) Sleet most commonly forms in the coldest areas of a band of freezing rain, usually the northernmost parts.

Graupel is formed in the same manner as hail, when updrafts catch frozen precipitation and lift it up repeatedly to be coated by layers of ice. However, while the core of a hailstone is an ice pellet, the core of a piece of graupel is a snowflake. Accordingly, graupel is both softer and, as a rule, smaller than hail.

Smaller hailstones are often compared to peas, coins and golf balls, while larger hailstones are similar in size to oranges, grapefruit, tennis balls, baseballs and softballs.

Where Is Hail Most Likely to Form?

Hail often is formed during severe thunderstorms, which feature both the updrafts that allow ice pellets to be caught up and built up into hailstones and downdrafts that can cause damage as straight line winds and microbursts or, if the winds begin to rotate, tornadoes. The more severe the storm, the stronger the updraft, and the stronger the updraft, the larger the hailstone can be.

(The National Weather Service defines a severe thunderstorm as having either hail of 3/4 inch, or dime-sized, in diameter or greater, damaging winds of 58 mph, or 50 knots, or greater – or both. Neither the presence of lightning nor how frequently it is striking has any bearing on whether or not a thunderstorm is classified as severe.)

Some severe thunderstorms, particularly those bearing hail, may turn the sky greenish. A number of scientists believe this is due to the water and ice within the storm cloud scattering wavelengths of light in the green portion of the visible spectrum, much the way the nitrogen in Earth’s atmosphere normally scatters the blue wavelengths of light to make the sky appear blue during a sunny day.

Although hail can form anywhere strong thunderstorms can hit (and Florida is the state where the most thunderstorms form), hail usually is most likely to form in thunderstorms over the Great Plains, and particularly in the states of Colorado, Nebraska and Wyoming, with the area where the three states meet dubbed “Hail Alley.” This is because the point at which the air is at the freezing point of water (32 degrees Fahrenheit) is closer to the ground here than at sea level. Other areas of the world where similar conditions occur include Russia, China, India, and the northern part of Italy. However, Colorado placed fourth in states filing the most hail damage claims in the first three years of this decade, with 118,118 according to the National Insurance Crime Bureau (NICB), after Texas (320,823), Missouri (138,857 and Kansas (126,490).

What Is The Difference Between a Severe Thunderstorm Watch and a Warning?             

Severe weather alerts are divided into watches and warnings. A watch is issued when severe weather conditions are predicted to occur. A severe thunderstorm watch is issued when conditions for thunderstorms are favorable. A severe thunderstorm watch typically covers a large area and may encompass part or all of several states. It usually lasts anywhere from four to eight hours.

A warning is occurred when severe weather is occurring or imminent. A severe thunderstorm warning is issued for an area where a severe thunderstorm is already happening or will happen within minutes. A warning usually lasts for one hour and does not require a severe thunderstorm watch to be issued prior to the warning.

A severe thunderstorm warning may be issued in conjunction with a flash flood warning if torrential rains are present or in conjunction with a special marine warning in coastal areas. If tornadoes are spotted in the area covered by the severe thunderstorm warning, it will be superseded by a tornado warning.

If either a watch or warning is issued, keep abreast of developments through a NOAA weather radio or through commercial radio or television.

How Can I Prepare Beforehand?

You can prepare for hail in two ways, by taking certain ongoing steps when the weather is good and other steps when the threat of severe weather looms closer.

Ongoing steps to prepare

Keep your trees trimmed. Remove any branches that have the potential of falling onto your house if a storm hits, as these would most likely be broken by hail or high winds.

Inspect your roof for potential trouble spots and fix them as they occur. Worn or missing shingles should be replaced immediately, and if your roof is near the end of the lifespan for its shingles, consider replacing it before hail season starts. This will reduce the possibility of hail damage. Look for impact-resistant roof materials that meet Underwriters Laboratories (UL) Standard 2218. Such materials are divided into four classifications, with Class 1 providing the lowest level of resistance and Class 4 the highest. Some states may provide tax credits for installing a UL-approved impact resistant roof; check with your state’s Department of Insurance or equivalent agency.

Check with your insurance agent to make sure you’re covered against damage from hail. You should be covered for the roof for your house or business building, as well as having comprehensive coverage for your principal vehicle(s). You may, however, have a higher deductible for hail damage than for damage caused by other means.

Monitor conditions for severe weather. You should have a NOAA weather radio; if not, pay attention to commercial broadcast radio and television to monitor conditions.

When a hailstorm is approaching

If you are at home or at work when a hailstorm is approaching, take the following steps:

  • Put all vehicles and expensive outdoor items under cover, preferably a garage.
  • Put large items (garbage cans, patio furniture) under cover, preferably a garage or shed.
  • Bring all outdoor pets indoors; shelter farm animals in barns.
  • Close all windows and doors.
  • Close the curtains over windows to block flying glass.

You do not have to go down the basement for hail, unless there is also a tornado warning; however, you do need to stay away from windows and skylights, which may be shattered upon impact by hailstones. If the only place away from panes of glass is in your tornado shelter, then you should go there. (See the previous posts in this series for items that should be part of your shelter.)

Once the hailstorm hits, do NOT go outside to rescue any stray animals or items. Although, as noted previously, you are not likely to be killed by being struck by hail, it can happen if the hailstone is large enough. Your property is not worth risking your life for.

If you are in a car or truck when a hailstorm is approaching, take the following steps:

  • Stay inside your vehicle. Hailstones fall fast enough to cause considerable injury, particularly when large.
  • Approach intersections cautiously. Treat any traffic signals as potential stop signs.
  • Don’t drive through standing water. You can read more about the hazards of trying to drive through floodwater on our previous blog at
  • Avoid downed power lines.
  • Get to a safe place, away from traffic, and stop the car. You can take shelter in a covered parking garage or under a gas station awning. Avoid pulling into a ditch, to avoid being caught in rapidly rising water.
  • Turn on your emergency flashers to make your car more visible if forced to pull over where there is inadequate shelter.
  • Erie Insurance’s website recommends you position your vehicle so the front windshield takes the brunt of the hail; it’s designed to withstand greater impacts than the rear windshield and side windows are.
  • Lie down, if possible, with your back to the windows. If you can get onto your vehicle floor, so much the better. If you have small children with you, cover their bodies with yours.
  • Cover yourself with a blanket, if available, to protect yourself from possible broken glass. If you cannot cover your entire body, shield your eyes with a cloth.

While taking the above steps will not guarantee your survival, they will greatly improve your chances of living to tell about it later. As always, use your best judgment.

What Should I Do After the Hailstorm is Over?

Assess the damage, wearing heavy shoes and thick, insulated gloves to protect yourself from broken glass, downed power lines and other hazards. (Avoid going into any areas where you know power lines are down.) Check your ground-level plants and shrubbery for signs of damage, as well as patio covers, screens and soft aluminum vents. If any of them show hail damage, your roof may be damaged as well. Also inspect your car for body dents and cracked or broken windshields, windows and mirrors.

Report the damage to your insurer as soon as possible. You should only need to provide a general description at this stage.

Make temporary repairs. Cover any holes in your roof or windows with plywood or tarps. Cover any holes or broken glass on your car’s windshields and windows and remove any loose broken glass from its interior. Move wet items to (relatively) dry ground. Clean what items you can. You may need the help of professionals to assist in the cleaning and patching process; they can be found by searching for “water damage restoration” or “contractors” online or in your telephone book. Save any receipts for your records.

Document your hail and other damage with photos, video, bills and receipts, as well as making a thorough list of what was damaged. Don’t throw out any damaged items until your insurer has helped you determine if the items are covered and how to proceed with their disposal and replacement.

Schedule permanent repairs with a licensed, bonded and insured local contractor. Your insurer may require you to wait to have the actual work performed until a claims assessor has visited you; however, contractors can be difficult to schedule after a storm hits, so you may wish to find and schedule a contractor contingent on your insurer’s approval. Allow only your claims assessor and the roofer you’ve selected onto your roof to minimize further damage.

Some things to note:

Choose a reputable roofer based in your area, if possible. While some out-of-town roofers are legitimate, a number of scammers have set up shop temporarily in areas where hail damage has occurred, collected homeowners’ money and then skipped town without finishing their work or paying suppliers.

Your roofer should have liability and workers compensation insurance in the event one of their workers is injured on the job or if they accidentally damage a neighbor’s property.

While your roofer may request a portion of the payment upfront, don’t make the final payment until you’ve had the work inspected and are satisfied with the quality.

You may use the opportunity to upgrade to better quality materials, such as replacing a fiberglass roof with a slate roof, but your insurer may only pay the replacement cost for materials of equal quality and require you to pay the difference for better quality materials. You should also consider the possibility of qualifying for a discount if you make certain upgrades, however, and determine whether you can recoup the added costs and how long it will take you to do so.

Resources and References:

Weather alerts

National Weather Service active weather alert map:

Interactive Hail Maps:

Weather education and research

The National Severe Storms Laboratory (NSSL): Severe Weather 101:

NSSL Hail Research page:

Insurance Institute for Business & Home Safety (IIBHS) Hail Research Page:

IIBHS: Disaster Safety Review issue highlighting hail research:

Hail damage prevention

National Roofing Contractors Association: Smart Steps to Reduce Hailstorm Damage:

Government disaster programs (FEMA)

State Directory of CERT (Community Emergency Response Teams) Programs:

Disaster Emergency Communications:

Equipment and training

The American Red Cross Store:

Finding Your Local American Red Cross Chapter:

Emergency communications

FEMA Family Communications Plan:

The American Red Cross Safe and Well Registry:



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