Its official! The hailstone from Vivian, SD is the largest ever in US history

[Chad Cowan]

I have a little video clip of the storm here:
http://www.youtube.com/watch?v=mZnmQ0mnTnU&fmt=22



And some more images online here:
http://www.chasethestorms.com/july23

A couple of my other favs, including a very concerned hound:

 

[Danny Neal]

Kevin had to replace the pic again, now yet another is up:

And now he is grabbing theories from around and passing them as his own. Get a Life kevin. It's obvious you are trolling here.

http://stormtrack.org/forum/showpost.php?p=280480&postcount=22

 

[Jim Saueressig]

http://stormtrack.org/forum/showpost.php?p=280480&postcount=22

Yep, I knew I had seen it before that one posted by sturgis which i assume is AKA Kevin as well.

P A Thetic

 

[cdcollura]

Good day all,

This hail size is down right scary. Anything getting hit with a hail stone like that would be equivalent to a light bowling ball tossed out of an airplane at 35,000 feet!

I would assume the updraft speeds with such a storm would be in the 150 to 200 MPH range (!)

Anyone have any numbers on the CAPE that day?

 

[Scott Weberpal]

Anyone have any numbers on the CAPE that day?

4000-4500 j/kg range...pretty typical for a chase day in the northern plains/upper-midwest this time of year.

 

[Mike Hollingshead]

Yeah it seems the bigger the cape gets past a certain point that more often than not you just end up with a storm producing less hail. I think the deal with this one was obviously a combination of several things. For one location west a good bit more towards high plains but east yet with very high dews for that far west. Think Philip was into the 70s early when I looked on the way there. That's real high for out there. The other thing, focused inflow region at the pinch point of a dryline arc and the warm front it was riding as well as turning on. Storm motion being quick, helping storm relative inflow further, all the while that being ese while having a strong sw upper jet given great storm-relative upper/anvil-level vent. I'm not sure that it would need any special circumstances past those and steep lapse rates. If there was one thing that could have, I'd guess it could have gotten a "bump" right after choking off the supercell moving up from behind it, and getting some even greater forcing/lift down low for a short bit there. Looks like that could have been close on radar to the timing at Vivian.

It probably didn't need any "bump" nor any bouncing stones from updraft over to updraft. Just was in an extremely favorable environment for big hail production and very sustained updrafts. Near and just south of that dl arc it was quite hot at and just off the deck too. Guessing that it had quite the mix of hot and moist air below the eml height in that area then. The cu south of the thing before Vivian just looked awful/hot. But obviously a lot of its inflow was moist along the warm front. Seems there was surely some really hot air getting mixed into that being right at the pinch point.

 

[Shawn Gossman]

This thing is crazy! It seems like this year is the year of severe weather record breakers and rare events!

@Chad - Love the black lab photo, looks just like my puppy

 

[James Hilger]

They cut it open here-http://news.yahoo.com/video/denvercbs4-15750663/it-s-the-biggest-hailstone-ever-recorded-in-u-s-21200081

 

[Lonnie Kopecky]

READ ABOUT HAILSTONE RECORD BROKEN IN AURORA, NE NEWSPAPER

If you are interested read what the folks at Aurora, Nebraska have to say about the broken hailstone record at auroranewsregister.com.

 

[Chance Metz]

Wow!

If I saw hail that big I would go into a bomb shelter! Biggest hail I have seen is maybe golf ball sized which is not really big.

 

[Chad Cowan]

Does anyone know how long a hailstone has to be suspended in an updraft in order to grow up to 8 inches? Obviously the updraft speed has to be greater than the terminal velocity of the stone in order to keep it suspended but I'm not sure how fast they can grow.

 

[Chance Metz]

Maybe 30 mintues or longer?

 

[Paul Knightley]

I guess the faster the updraught velocity is, the more 'material' passes across the developing hailstone per second. And the larger the hailstone is, the more surface area it exposes to the material, perhaps accelerating the growth.
Regarding the 'jumping' theory: would the upper winds not have to be favourable to move it from one updraught to the other? We already know that very big hail only falls close to the updraught, so it would be very hard to move a stone from one updraught to the next.
I was wondering whether there was any way the hail might be caught by the rotation of the mesocyclone, and take more of a spiral journey up through the storm rather than straight up - this would prolong the time it could stay in the updraught, and in the favourable mixed phase of the cloud layer.

 

[Chance Metz]

Yeah anyone who steals other ideas loses all credibilty. That makes it even less likely that anyone will belive any of his "stolen" theories.

 

[Mike Hollingshead]

http://www.extremeinstability.com/2010-7-23.htm

Finally got a full account up of that day now. Just wasn't a lot of time to get still images of the thing.