Vivian Hail Stone

Note: This report was originally compiled and published by the National Weather Service Weather Forecast Office in Aberdeen, SD. It has been preserved here to accompany the associated NCEC Record Event Report. The web page was retrieved on 5 January 2011 from http://www.crh.noaa.gov/abr/?n=stormdamagetemplate. This document will not reflect any changes made by WFO Aberdeen since that date.


Summary

During the late afternoon and early evening hours of 23 July 2010, thunderstorms developed over portions of central South Dakota. Several storms quickly became severe in an environment favorable for supercell thunderstorms. In particular, one very strong supercell thunderstorm moved southeastward across portions of Stanley, Jones, and Lyman counties. One of the hardest hit locations was the community of Vivian, South Dakota, where extremely large hail, destructive winds to 80 mph, and a brief tornado were reported.

A record setting hailstone was ultimately discovered in Vivian, measuring 8.0 inches in diameter, 18.625 inches in circumference, and weighing in at an amazing 1.9375 pounds. This hailstone broke the previous United States hail size record for diameter (7.0 inches - 22 June 2003 in Aurora, NE) and weight (1.67 pounds - 3 September 1970 in Coffeyvile, KS). The Aurora, Nebraska hailstone will retain the record for circumference (18.75 inches).

The hailstone's official record dimensions were as of the time personnel from the NWS in Aberdeen first observed and measured it. The stone did shrink considerably (melting and sublimation) between impact and when it was first measured by NWS personnel due in part to a power outage at the residence of the individual who found the stone. It should also be noted that many other stones with diameters exceeding 6 inches were also noted during the storm survey.

NOAA Press Release

Hail and Damage Photos

Mower County
Diameter = 8.0 in
Mower County
Circumference = 18.625 in
mower county 2  Freeborn County
Weight = 1 lb 15/16 oz (1.9375 lbs)
Freeborn
Hail Divot
Freeborn
Hail stone crashes through deck

Radar Imagery

radar image from 1055 p.m. June 26 2010
0.5 Degree Reflectivity Loop of Event
radar image from 1055 p.m. June 26 2010
4 Panel Radar Reflectivity valid at 2258 UTC (0.5, 0.9,1.3, 1.8 degrees)
radar image from 1055 p.m. June 26 2010
4 Panel Storm Relative Velocity valid at 2258 UTC (0.5, 0.9, 1.3, 1.8 degrees)

The storm scale structure of the storm was very impressive. In the images above, three body scatter spikes (TBSSs) are noted at several elevation angles at 2258 UTC. In addition, a very pronounced bounded weak echo region (BWER), and very intense mesocyclone are also indicative of a strongly rotating updraft.

Initial estimates indicate that the updraft strength in the Vivian hail storm likely ranged from 160-180 mph.

Additional Storm Reports from July 23, 2010

July 23, 2010 Storm Reports
Time Event Location County/State Remarks/Source
5:15 PM
07/23/2010
1.50 Inch Hail 10 S Akaska Potter, SD From: MESONET
5:33 PM
07/23/2010
1.00 Inch Hail 6 E Hayes Stanley, SD From: CO-OP OBSERVER
5:35 PM
07/23/2010
1.25 Inch Hail 8 ESE Hayes Stanley, SD From: TRAINED SPOTTER
5:35 PM
07/23/2010
1.75 Inch Hail 6 E Hayes Stanley, SD From: TRAINED SPOTTER
5:45 PM
07/23/2010
1.50 Inch Hail 10 N Murdo Jones, SD DAMAGED SIDING AND BROKE WINDOWS
From: PUBLIC
5:48 PM
07/23/2010
85 mph Thunderstorm Wind Gust 4 NNE Draper Jones, SD APRS SITE
From: MESONET
5:57 PM
07/23/2010
Tornado Vivian Lyman, SD LAW ENFORCEMENT RELAYED A PUBLIC REPORT OF A TORNADO EAST OF DRAPER...NEAR VIVIAN
From: LAW ENFORCEMENT
6:00 PM
07/23/2010
1.75 Inch Hail 8 N Vivian Lyman, SD GOLF BALL HAIL
From: PUBLIC
6:10 PM
07/23/2010
1.75 Inch Hail 1 W Seneca Faulk, SD From: LAW ENFORCEMENT
6:10 PM
07/23/2010
4.75 Inch Hail Vivian Lyman, SD SOFTBALL SIZE HAIL. POSSIBLE TORNADO SPOTTED 2 SOUTH OF VIVIAN.
From: LAW ENFORCEMENT
6:10 PM
07/23/2010
1.75 Inch Hail 1 W Seneca Faulk, SD From: LAW ENFORCEMENT
6:15 PM
07/23/2010
1.75 Inch Hail Seneca Faulk, SD From: CO-OP OBSERVER
6:22 PM
07/23/2010
1.75 Inch Hail Presho Lyman, SD HAIL AND 70 MPH WINDS
From: CO-OP OBSERVER
6:35 PM
07/23/2010
2.00 Inch Hail Lyman Lyman, SD GOLFBALL TO HEN EGG SIZE HAIL WITH 60 MPH WINDS
From: STORM CHASER
7:00 PM
07/23/2010
3.00 Inch Hail 6 SSE Kennebec Lyman, SD COCORAHS SPOTTER...DURATION OF HAIL 20 MINUTES
From: TRAINED SPOTTER
7:04 PM
07/23/2010
73 mph Thunderstorm Wind Gust Oacoma Lyman, SD From: MESONET
7:49 PM
07/23/2010
60 mph Thunderstorm Wind Gust 2 SW Doland Spink, SD From: PUBLIC
7:50 PM
07/23/2010
Tornado 6 S Doland Spink, SD MINOR DAMAGE TO FARMSTEAD AND TREES. PRELIMINARY WIND SPEED ESTIMATED AT 80MPH CONSISTENT WITH EF0 RATING
From: PUBLIC
7:50 PM
07/23/2010
1.75 Inch Hail Doland Spink, SD From: PUBLIC
8:00 PM
07/23/2010
60 mph Thunderstorm Wind Gust 3 SSW Raymond Clark, SD From: PUBLIC
8:58 PM
07/23/2010
60 mph Thunderstorm Wind Gust 2 N Bryant Hamlin, SD DIME HAIL REPORTED WITH THESE WINDS
From: TRAINED SPOTTER

Meteorological Analysis

The images below depict the synoptic and mesoscale environment at 22:00 UTC (6PM CDT) - about one hour before the record hailstone fell in Vivian. Note that the kinematic and thermodynamic environment was very supportive of supercell thunderstorms due to the high shear and high CAPE environment.