Topic: Giant hail South Dakota, USA: 21 August 2007

[Macca]

Hi all,

Just stumbled across this on another weather forum...

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE
SIOUX FALLS SD
240 PM CDT WED AUG 22 2007

..DANTE SOUTH DAKOTA HAILSTONE OFFICIALLY MEASURED AT 5.25 INCHES..

LARGE HAIL FELL ACROSS PORTIONS OF SOUTHEAST SOUTH DAKOTA TUESDAY EVENING AUGUST 21 2007. THE SMALL COMMUNITY OF DANTE...IN SOUTHEAST CHARLES MIX COUNTY...TOOK A DIRECT HIT FROM THE LARGE HAIL. MOST HOMES IN DANTE SUSTAINED CONSIDERABLE HAIL DAMAGE...WITH HOLES PUNCHED IN ALMOST EVERY ROOF IN TOWN BY THE LARGE HAIL. THE NATIONAL WEATHER SERVICE SURVEYED THE DAMAGE AND FOUND THE LARGEST HAILSTONE TO BE 5.25 INCHES IN DIAMETER. THIS HAILSTONE WAS NOT PICKED UP FOR 10 TO 20 MINUTES AFTER IT FELL...SO WAS LIKELY LARGER WHEN IT HIT THE GROUND. THE LARGE HAIL CREATED CRATERS UP TO 10 INCHES BY 12 INCHES IN THE YARDS THROUGHOUT DANDE. THE LARGEST HAIL FELL AT APPROXIMATELY 610 PM ON AUGUST 21 2007. WHILE UNUSUALLY LARGE AND VERY DAMAGING...THE DANTE HAIL DOES NOT SET A NATIONAL OR STATE RECORD. THE NATIONAL RECORD HAIL IS 7 INCHES ACROSS...MEASURED AT AURORA, NEBRASKA ON JUNE 22 2003. THE SOUTH DAKOTA RECORD...SINCE 1950...APPEARS TO BE 6.00 INCHES IN CUSTER COUNTY ON JUNE 22 1968. MORE RECENT NOTABLE LARGE HAIL IN SOUTH DAKOTA INCLUDES 4.25 INCHES 2 MILES SOUTH OF DELMONT IN DOUGLAS COUNTY ON SEPTEMBER 16 2006 AND 4.25 INCH DIAMETER HAIL IN SULLY COUNTY 8 MILES WEST OF AGAR ON AUGUST 24 2006.

An image of some of the hailstones is here...

http://www.keloland.com/ClassLibrary/Page/PhotoAlbum/Images/Photos/ph_3699.jpg

5.25 inches is a little over 13cm!! AWESOME stuff.

Just a little addition...this is the latest news...

"Right now our largest is at 7"x3.5"---nice lobe of ice! That report was accompained by the witness stating that the hail was penetrating car hoods."

"The photo and information about the location of the giant hail have been passed along to FSD, and it's important to remember any dimensions are unofficial until the FSD NWS office has had a chance to review all the information and make an official decision."

So...do we call this ELEPHANT hail (since it is clearly bigger than a gorilla...)?

The photo they refer to is of the 7" stone (7" = 17.5cm!!!!!!!!!).

Macca

[Jimmy Deguara]

Macca,

Yes I keep getting amazed at the particularly large hail sizes they can observe in the United States.

Do you think it may have been popped out of the anvil - the severe storm breakdown? What were the conditions in terms of approaching upper trough and extreme CAPE in the region?

Regards,

Jimmy Deguara

[Jimmy Deguara]

Hi,

Here is another source of the hailstones from the 21st August 2007 hailstorm (Photographs courtesy Todd Heitkamp, NWS, Sioux Falls, South Dakota

http://www.crh.noaa.gov/crnews/display_story.php?wfo=fsd&storyid=9811&source=0







Regards,

Jimmy Deguara

[Jimmy Deguara]

Here is the splitting supercell near Dante according to radar:

Prepared by Jeff Snyder on Storm Track


It became tornado warned. There are unofficial reports of hailstons 6" to 8" in diameter but nothing measured thus far.

Here is another article with picture of the hailstones in a park:

http://www.keloland.com/NewsDetail6162.cfm?Id=0,60173

http://www.keloland.com/NewsDetail6162.cfm?Id=0,60171  impressive hail damage!

and of course the image linked above by Macca


Regards,

Jimmy Deguara

[Shaun Galman]

Hi all,
That hail is unreal!!! Imagine being stuck out in a field somewhere with that coming down! "Now where did I put my helmet?" I cant fathom how loud it would be hitting a house roof, even small hail makes it hard to hear anything! I'd love to catch something similar out here (away from town and civilisation) it would make photography a challenge and more than a little interesting to say the least!

We had a severe storm out on the Coocoran Opal Fields back in 2000 with 3-Inch + hail recorded, according to the poor souls camped out there in caravans and camps, it was a nighttime event unfortunately so no pictures to share? Largest I've heard of here, nothing compared to the images above though. Must've been one heck of an amazing supercell thats for certain!

Cheers.
Shauno.

[Jimmy Deguara]

Shaun,

I am not sure what you have observed in the past but I will attempt to give you some indication of how serious this hail is.

Being out in a car in an event like that will make you think whether you should write out your will! Hailstones of this category - especially if the 7 inch hailstone can be properly verified will crack through the metal of your car! Hail of the 4"+ mark with the strong winds could cause serious injuries or even death!

I have witnessed hailstones of the 4 inch but only a few hailstones mostly hailstones of the 8cm mark but relatively no wind! Anything larger could have caused injuries - with wind we would have sustained extensive injuries and I have heard storms with larger hailstones and wind required hospitalisation treatment for those caught in it. I mean only 4 inch type of hail!

Imagine what larger hail than the following can do:

http://www.australiasevereweather.com/video/movies/2005/0220jd01.wmv

http://www.australiasevereweather.com/video/movies/2005/0220jd02.wmv

And Michael's footage of a separate storm:
http://www.australiasevereweather.com/video/movies/2004/1109mb01.wmv

I think the concept of helmet offers only an acute sense of security:)

Just for the record, the frequency of hail events in the range of 3" and greater range are relatively rare in this country. Such events in the United States are not uncommon - in fact realively frequent particularly duirng outbreaks. I know each season in the US, hail to 5" or greater will occur at least once or twice somewhere.

Regards,

Jimmy Deguara

[Michael Bath]

Impressive hailstones alright !!!  Certainly is quite rare to get the 10cm plus here compared to the US. Just don't get the setups of course. Here's the GFS analysis for some comparisons.


Links to GFS Analysis: 22/08/2007 00z

Instability: CAPE / Lifted Index

Relative Humidity: 0300 / 0500 / 0600 / 0700 / 0850 / 1000

Temperature: 0300 / 0500 / 0700 /  0850 / 1000

Winds (knots): 0200 / 0300 / 0500 / 0600 / 0700 / 0850 / 0925 / 1000

Fixed those temp links now.

[Jeff Brislane]

The look on that guys face holding the hailstones is classic! And think of the size of the hail craters in the ground and compare that size to your own head! How do people not get killed by hailstorms like this? And where is dante in relation to the supercells on the radar pic?

[Mike]

In that radar image - is that a meso and small hook developing in the lower SW corner of the cell?

The footage from the local hail is just unreal.  I think 'Holy Smokes' is an understatement and once you're in it the damage is done!  How is hail that size born at all - is it through the shear size of the storm itself?  (tower size)

Mike

[Michael Bath]

Yes it is a hook echo - this image was posted on Storm Track and elsewhere

MB

[Jimmy Deguara]

And as usual, it is pictures like these that make me cry - not uncommon with these explosive events!

Check out Mike Hollingshead's images from the storm!
http://www.extremeinstability.com/07-8-21.htm

Please promise - no tears.

Regards,

Jimmy Deguara

[Mike]

Your'e not wrong Jimmy!  Spectacular mammatus shots - you can't feel all that bad, spare a thought for those of us that have never seen any supercells! Mike Hollingshead certainly got his tank full of 'gas' worth.

Mike

[enak_12]

Yes incredible isn't it Jimmy. I've read that the largest recorded Australia hailstone was 14cm. Anyone know if this is official? I guess it must be since I found this on the BOM. I've also read of one 14cm falling at Kempsey.  http://www.bom.gov.au/weather/nsw/sevwx/hailfact.shtml

[Michael Bath]

The 14cm at Kempsey was a report from this thunderstorm that I also witnessed:
http://australiasevereweather.com/photography/photos/1991/mb19911221.html

Not sure if the measurement was ever verified. That BoM table has 14cm for the Northern Rivers - should be Mid North Coast if it's referring to the Kempsey event.

[enak_12]

Thanks for that Micheal. Would  of made an awesome photo much like the recent one from the USA if it was true. How big were the ones in your photo's? They appear to have melted a fair bit despite still being very large.