Category: 

How does Hail Form?

Handful of hailstones.
Hail can occur during a thunderstorm, but not all the hail that forms will always remain intact.
The swirling updrafts of a tornado are ideal for hail formation.
When the winds inside a storm cloud begin to circulate, a powerful updraft can pull dust particles, insects or tiny ice crystals up to the cloud's highest levels.
Hail may form during severe thunderstorms.
Article Details
  • Originally Written By: S. Mithra
  • Revised By: A. Joseph
  • Edited By: L. S. Wynn
  • Last Modified Date: 04 September 2014
  • Copyright Protected:
    2003-2014
    Conjecture Corporation
  • Print this Article
Free Widgets for your Site/Blog
Mickey Mouse was the first non-human to win an Oscar.  more...

September 20 ,  1873 :  The Panic of 1873 caused the New York Stock Exchange (NYSE) to shut down.  more...

Hail forms when tiny clumps of ice, kept aloft by strong updrafts, get blown through freezing thunderclouds until they are heavy enough to fall to earth. Most large thunderstorms create some hail, but the proper conditions must be present for the hailstones to grow large, freeze solid and then survive until they reach the ground. The ideal conditions for hail are tall clouds that reach high into the atmosphere, many swirling updrafts such as in a tornado and cold temperatures within and beneath the storm.

Starts with a Nucleus

A hailstone begins to form as an ice nucleus, a small cluster of supercooled water droplets or clumps of snow. This center might continue to accumulate ice, melt in the thundercloud and turn to rain or be smashed apart by other clusters. If a bug, a piece of dirt, a seed or another small particle gets blown up into the storm cloud, it creates another possible nucleus for a hailstone.

Layers of Ice

If the thunderstorm is cold and windy enough, this ice cluster will accumulate layers of ice the way a dipped candle accumulates layers of wax, through a process called accretion. Opaque, whitish layers form when icy droplets trap air bubbles and stick to the cluster. Clear layers have accreted large drops of supercooled water that freeze when they encounter the hailstone. Of course, much larger hailstones can be made when two smaller ones freeze together.

Ad

Gaining Weight

Hail can accrete more layers when the hailstone blows up through layers of the thunderstorm. Even heavy hailstones can be kept aloft by strong enough updrafts. When the hail falls back through the storm because of gravity, it accretes even more layers, until it is so heavy that it falls as precipitation. Hailstones form in most tall, cumulonimbus storm clouds that reach the colder upper atmosphere, but not all hail survives after it is out of the thunderstorm. A few outer layers frequently melt when the hail mixes with other precipitation, such as snow and rain.

Sizes

The size of fully formed hailstones can vary from pinheads to softballs. There are official size categories for hail that are useful for gauging the damage that they can cause. Some hailstones have been measured at more than 6 inches (15.24 cm) across and more than 1 pound (0.45 kg) in weight. Most hailstones, however, are less than 0.5 inches (1.27 cm) across.

Ad

More from Wisegeek

You might also Like

Discuss this Article

anon117018
Post 75

Thanks for the information. We had one just recently here in fiji and it was really shocking for everyone because it had never happened before. The information was really helpful. Thanks once again.

anon72400
Post 68

Wow! this thing is like so good. i got like 59/50! that's like more than 100 percent! thanks so much!

anon69876
Post 67

This thing gave me so much info that i got an +A on my project! Thanks a bunch!

anon69632
Post 66

yeah! thanks dude for the info. this website is pretty good has good info. thanks. got my work done.

anon69522
Post 65

That really helped as well. we just had a hail storm in Melbourne, Australia on the weekend and we had to know how hail was formed and this was useful. Thanks!

anon64593
Post 58

wow! i am doing a project bout weather and land stuff like that so i am hoping that somebody can help me?

anon63139
Post 57

thank you very much for posting this article. it helps me a lot on my assignment. -micheal

anon61692
Post 55

thank you for putting up this site. it's helping me finish an assignment that's going to boost my grade up cause right now I'm failing so this website is a lifesaver!

anon56152
Post 52

thanks wisegeek. Interesting! --pink*

sisibabi
Post 50

Thanks bunches!

anon51700
Post 48

The information on this website is very good

anon51185
Post 46

thank you so much. i will be referring to your site more. this helped me with school and it was really nice. i got a 100/100 on the power point and paper.

anon50265
Post 45

this helped me with school.

anon49995
Post 44

awesome site.

anon48761
Post 43

i got extra credit. thanks a bunch! :)

anon48760
Post 42

Thanks so much. My kids wanted to know how hail formed and this explanation was just the ticket.

anon47928
Post 41

Thanks so much! this really helped with my test!

anon46033
Post 40

This is just what i needed for a project! I can't believe i finished everything on one page. Thanks. god bless you!

anon41314
Post 38
anon41313
Post 37

This is very useful for my homework! just 1 quick question: what are water vapours?

anon38521
Post 36

thanks heaps for all this info.

anon25065
Post 28

It really helped me with my homework...I have to learn about hail storms and how it is formed

anon24655
Post 27

yeah, I was studying for midterm exams and this really helped, thanx XD

anon24231
Post 25

this really helped in my homework THnX !!

anon24230
Post 24

this was exactly what I needed. It really helps when you can find a sight that tells you just what you need, not all sorts of other nonsense. This really helped me with my homework. THANKS!!!

anon23005
Post 22

thnx so much, this really helped me with my science project due tomorrow! i hope u have information on stuff besides hail so i can use it! thanx a bunch wisegeek!

anon22754
Post 21

thanks a bunch i really really needed this for science my teacher would SPAZ if i didn't do it

hannahrose
Post 20

i was doing a research article in school on hail storms and i clicked on this link and gave me everything i needed to know thank you you were much better than that stupid highbeem place!

anon21558
Post 19

thnx 4 thiz info on hail. i needed to know how hail was formed and how it falls from the sky 4 but because i needed to write a myth on hail, but had to have a reason or something on hail and stuff like that. but thnx again i was able 2 learn something very interesting by also getting an idea for my myth!!ive learned from just reading ur article that hail sounds pretty cool but pretty dangerous at the same time.but this info. was also very helpful!!thnx a WHOLE BUNCH WISEGEEK!!!!!

anon20128
Post 17

this really helped with my last minute science project.

anon19796
Post 16

i love this site. this really helped me on my science project that im doing last minute.

anon18911
Post 14

this was exactly what I needed. It really helps when you can find a sight that tells you just what you need, not all sorts of other nonsense. This really helped me with my homework. THANKS!!!

catapult43
Post 13

Not long ago, while vacationing on the Adriatic coast, in the middle of the night we got severe storm with lightning, thunder and hail. Hail, the size of a golf ball was coming down in sheets. Even though it was night, but with all the street lights still on, the visibility was down to zero.

The force and speed of hail did a lot of damage. All the leaves were stripped of all exposed plants, and only empty stems were left sticking out. Luckily, even though the storm came down with force, it wore itself out reasonably quickly. It was an unbelievable sight and experience.

anon12680
Post 12

this site is so cool. i can find like almost everything. wise geek company thank you for making this site. whenever i need info ur sure im going to be on your site ty.

anon11972
Post 11

this page really helped with an upcoming test i have which i am studying for last-minute. I found u guys and i think it really cleared up a few questions i had. Thanx!!

anon11354
Post 10

this helped with my homework, but i got only a A and not a B+

anon8404
Post 6

thanks ever such a lot wisegeek, u rock. i am coming back on here-deffo! when i started doing my homework i thought all the websites would bring up a load of old rubbish with info that isn't needed, but u didn't- thnx again!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

luv,

anonymous

anon7249
Post 4

i was just searching for the how hail forms thing on the net and this popped up at the very front. it gave me EXACTLY what i wanted. it helped so much. thank you (especially for not giving all the extra info other sites tend to give)

anonymous

anon6972
Post 3

This really helped me on my homework!

Thanks ever so much!

anon6615
Post 2

Thanks so much wise geek company you guys helped me out on my science homework so much you explain it in words i can actually understand. i am going to come back on your site for more help thanks so much!!!!!!!!!!

Moderator's reply: that's what we like to hear! hope you ace your homework!

anon260
Post 1

i love your wise geek page it really helped me out on my science project i just wanted to post a comment to thank the wise geek company!!!!

Moderator's reply: You're very welcome! Always happy to hear our users are finding the information they need!

Post your comments

Post Anonymously

Login

username
password
forgot password?

Register

username
password
confirm
email