Biggest Hail Climatology/Best Hail Video

[Adam Adkins]

I have been interested lately in what causes big hail (4" or larger) to fall where it does. If you look at archived storm reports, there are some obvious signs such as CO, KS, OK, TX, NB, SD, IA, and MO, which has the highest frequency of very large hail because of how close they are to the freezing level (elevation), and frequency of supercells. But what about other areas? Colorado does not have the extremely big (4.5"+) hail that they do just east, despite it being so close to the freezing level. Then, there is a belt from SW of Atlanta northeast into central NC where these are more common (and tornadoes for that matter). Is that the result of some kind of forcing from the Appalachians?

Lastly, what is your nomination for best big hail video? I think these are the best storm videos, and really big hail is rare to catch! What are your favorites?

 

[Mike Ridgeway]

Great post Adam, and I'm only adding to it. I sometimes hear about chasers reporting softball size hail. I have not personally seen it, although it would be cool. A softball has a circumference of 12 inches, although in some Chicago leagues it is 16 inches. I know because I grew up there. So how many of you have actually seen softball size hail? There must be some monster updrafts associated with stones of this size, and I'm guessing tornadoes would be a given. I can't imagine what the ground would look like with softball size hailstones all over the ground. Pics anyone?

 

[Marcus Diaz]

Adam...higher elevations don't see the massive 4.5"+ stones usually because of the lack of a thick moist layer. Moisture has to travel upslope, so there's not the really dense layers of moisture you'd see further east. What the elevation does have is, well...elevation. Being higher up, it is closer to freezing than anywhere at sea level. This in turn means that storms with enough instability to work with combined with less distance from freezing level to the surface means large quantities of hail. So places in or very near the mountains can worry about hail accumulations more commonly.

 

[Adam Lucio]

The gorilla stuff tends to form on very high CAPE days. Im talking 3500+. Those are the days I've noticed I more frequently encounter the monster stuff. LP type structures can be prolific hail makers as well. Generally when you get an environment that is too warm and moist, hail production tends to be limited. I don't think mountain ranges have too much of an effect on the real monster hail, but the fact theyre more adjacent to colder mountain air means the freezing level within the storm is often lower, so you get MORE hail producers in the quarter - golfball range. Those types of areas often lack the major CAPE needed to get the softballs though. I also noticed while chasing that when I encounter large hail, the updraft tower has a visual appearance of being straight up as opposed to tilted. I think the shear/cape/moisture combo has to be just right.

This storm dropped the largest hail I have seen on a chase with some stones over 6" - luckily I wasn't under this atomic updraft when those bowling balls were falling. Demolished cars were lined up along the interstate just a couple miles down from where I snapped this photo.

 

[Adam Adkins]

Very interesting responses. Big cape days get the biggest hail. It makes sense though because the highest I've ever seen over eastern CO is 3500. Although Fort Collins (which is right along the mountains) has seen 5", the biggest recorded in CO. So far west!

Adam what date was that photo?

And what about best big hail videos? Any nominations? Here's one of my nominations:

 

[Stephen Szulborski]

Unfortunately or fortunately due to location being from Michigan, the largest hail I have seen has only been 2.25"

As for hail videos, I have to introduce the hail storm in OKC on May 16th 2010

As you can see in the video it absolutely destroyed the vegetation with baseball sized hail.

 

[Mike Marz]

I have chased storms that I expected to have huge hailstones due to the extreme CAPE available on those days, but the stones I encountered were not much larger than golf balls. One such example is June 17th, 2014. The CAPE on that day was very high, and when we had to approach that storm from the north, I was expecting some pretty big sized stones, but luckily we only experienced a lot of dime sized to golf ball sized hail. I did see some stones that appeared to be closer to tennis balls falling pretty near our location, but these were few and far between. I have also experienced some tennis ball sized hail on days where the CAPE was not nearly as extreme, and on a storm that didn't produce a tornado, as far as I know. As far as a good hail video, I am sure many have seen this one, but it is pretty intense.

 

[Ben Holcomb]

I love a big hail video. One of the more memorable chases I ever had was with @Hans Schroeder and @Steve Miller in 2009 where we ended up in baseballs or bigger in North Texas. @Shane Adams was actually driving my truck as he didn't have a vehicle to chase and I was chasing with Hans and Steve. I laugh like an idiot as I watch the big hail denting the crap out of my truck and Hans' Expedition.

 

[Adam Adkins]

That is a good one.

May 10, 2010 was a date that produce some of the biggest stones I've seen on video. Look at these multiple 5"+ stones falling like bombs. Extreme shear and CAPE day.

Or look at 5:05 in this video from the same day. What is this like a 6" hailstone?? What a meteorological setup this was!

 

[Adam Adkins]

And one last one from the same storm. This really shows how it sounds from inside.

 

[StephenHenry]

Those 2010 OKC hail videos are definitely some of the most impressive ones out there. But this Woodward example delights me on so many levels.

 

[James Hyde]

One of the more recent events that comes to my memory is the Abilene,TX storm on June 12 last year. One 4.5" LSR.

 

[Stephen Szulborski]

One of the more recent events that comes to my memory is the Abilene,TX storm on June 12 last year. One 4.5" LSR.

View attachment 6518
View attachment 6517

One of my former coworkers who is now at NWS San Angelo did the storm survey for this hail event. He said it was some of the worst hail damage he had ever seen and he would not have been shocked if there were some hailstones over 5" during the storm. I believe the cost of the event was somewhere in the 350 to 400 million dollar range.

 

[jaredleighton]

I'm not sure there is a really strong geographic signal for giant hail. In other words it likely happens a lot more frequently than we think. The problem with the giant hail climatology, well...hail climatology in general, is that it's so dependent on StormData, which is pretty lackluster. That's of no fault of the NWS, because the documentation is dependent on the hail actually hitting residents, and those residents actually reporting the hail...which happens much less frequently than you might imagine, strangely enough.

For example, if you'll excuse the irresponsible story telling (since I heard this second-hand), the Vivian SD 8" stone was never reported to the NWS. From what I understand they were out surveying a weak tornado, and either the EM or a resident talked about his neighbor picking up a monster stone and preserving it. If that turns out to be untrue I'll redact the anecdote. But the point remains. I surveyed a giant-hail producing storm with Scott Blair back in Sept 2010 that hit Wichita. The findings of that survey can be found in this paper that we published in the EJOM ( http://www.slightrisk.net/yahoo_site_admin/assets/docs/EJOM_ICT_Hail.34700408.pdf ). The main discussion of the article was that while a 7-8" hail-producing storm went right through the Wichita metro, the NWS received around 30 reports. However a perusal of social media yielded several hundred reports. While social media will help with the future climatology of hail, it doesn't offer much for the historic documentation.

I worked with several fine Mets on a paper regarding giant hail climatology and detection, and if you're interested in learning how to use radar to try to interrogate 4+" hail in a supercell, which can come in handy for chasers, then I recommend the following piece by Blair et al. ( http://www.ejssm.org/ojs/index.php/ejssm/article/view/87/67 ).

One more piece to look at if interested is a presentation Blair et al. did at the 2014 SLS in Madison, WI, regarding the "true hail-fall characteristic" of a storm vs what we believe to be the hail-fall characteristic. He has completed 4 years of hi-res hail documentation and compared it to the historical documentation. The results will likely surprise you....or maybe they won't. https://ams.confex.com/ams/27SLS/webprogram/Paper255707.html

The good news with the above recommended reading pieces is that they are very easy to read and digest. There isn't much in the way of technical meteorology in them. But they offer some pretty valuable insight into the reality of hail frequency and detection, which is very important for chasers to understand, especially when it comes to deciding which storms to mess with and which ones to leave alone. The general findings are that there are A LOT more of these giant-hail producing storms than anyone ever considered.

 

[Dan Robinson]

As Jared said, the hail report data is a little like the F/EF scale with rural vs urban tornadoes - if a storm produces giant hail in rural areas, its biggest hailstones are less likely to be observed and reported. A storm that is 'fortunate' enough to traverse a metro area is more likely to have its largest hailstones documented.

Historically, the record storms in terms of damage haven't been ones that produced record-sized stones, but are the ones that struck large metro areas. St. Louis' two events in 2001 and 2012 (both all-time US records at #1 and #2 spots) primarily contained 3" stones maximum. A 4.5" stone was reported with the 2012 storm, but it was an isolated instance.