As bands of thunderstorms have made their way across North Texas in recent weeks, hail has repeatedly been one of the forecast hazards.
Lots of counties in the western part of the region have seen significant hail fall, including several reports of hail over 2 inches in diameter in storms at the start of June.
Curious where hail comes from or how to protect yourself when it arrives? Read more below:
How does hail form?
When a raindrop is carried by a thunderstorm updraft to an extremely cold part of the atmosphere, it will freeze and create a small hailstone. It grows in size as other liquid water droplets collide with the hail and freeze onto the surface, according to the National Severe Storms Laboratory.
When the updraft can no longer the weight of the hail, or the gust weakens, the hailstones will be dropped from the sky. Surface winds can also impact the angle at which hail falls, sometimes causing it to make impact diagonally or horizontally.
How does hail compare to other kinds of frozen precipitation?
Snow forms when water vapor freezes into ice without ever being a liquid. Snow can sometimes then turn into graupel, which are soft pellets that form when water droplets freeze on the exterior of a snowflake.
Sleet forms from the freezing of rain droplets that do not grow in size. If sleet or graupel collect extra ice on their exterior, they can become hail. Hailstones must be at least 0.2 inches in size.
Size guide
Hail is often discussed in reference to the size of common objects. Here’s a guide from the National Weather Service’s Fort Worth office:
| Reference object | Measurement (inches) |
|---|---|
| Pea Size | 0.25 |
| Marble Size (Plain M&M) | 0.50 |
| Penny Size | 0.75 |
| Nickel Size | 0.88 |
| Quarter Size | 1.00 |
| Half Dollar/Ping Pong Ball Size | 1.50 |
| Golf Ball Size | 1.75 |
| Hen Egg Size | 2.00 |
| Tennis Ball Size | 2.50 |
| Baseball Size | 2.75 |
| Grapefruit Size | 4.00 |
| Softball Size | 4.50 |
How big does hail have to be to cause damage?
To be considered severe, hailstones must be at least one inch in diameter. Multiple auto body shops or roofing companies with pages about hail similarly say that hail one inch in diameter or greater is generally the threshold to require repairs.
How to stay safe in a hail storm
The U.S. Forest Service said for those enjoying the outdoors when caught in a hailstorm, it is important to seek immediate shelter. If it is not possible to protect one’s entire body, one should focus on the head.
If driving, the forest service recommends pulling over and waiting inside the car for the hail to . It suggests avoiding parking near large trees in case other storm hazards cause them to fall over. Nationwide Insurance said it is important not to park under overes, which can flood. It also recommends getting on the floor or backseat of a car face-down to avoid getting hit by broken glass.
A garage is the best way to protect a car against hail, but thick blankets or mats can also help soften the landing if covered parking isn’t available.