Hail forms with an uplift that involves air rising, cooling and condensing as the temperature goes down. Discover how hail can get larger through winds that pick it up and coat it with more ice with help from the chair of a department of environmental studies in this free video on hail.
Well hail forms just with the uplift. As that air is going up, alright, it's cooling and condensing, you get the droplets of water forming first. Well as it continues to rise and gets higher and higher up in the atmosphere, obviously the temperature is going down, it's getting cooler and cooler. Well if it gets high enough where the temperature is low enough, that water will freeze. So those little droplets start turning into little ice balls. Now what will happen many times is they'll rise up into the atmosphere, of course once they freeze they'll start to fall down through the atmosphere. If the winds are strong enough, they will pick them up and bring them up again, they'll get coated with another layer of water, they'll refreeze, they'll drop down again, it will happen again and again. So in very intense thunderstorms, you can get very large hail. If you watch the Weather Channel and so on, sometimes you'll see hail that's the size of sometimes it'll get up to softball size. Well what's that telling you? That's telling you that you have extremely strong updrafts, extremely strong winds, something that will basically push a snowball, the size of a snowball, in the air and move it up. So you're talking winds of in the hundreds of miles an hour to move this thing up. If the winds aren't so intense, well then you get the pea size or the gravel size or the golf ball size hail. So again, it depends on how strong those updrafts are, how cold it is and how fast can you can freeze that stuff.