Alert archive / South Dakota / Severe Thunderstorm Watches in 2007

Severe Thunderstorm Watch 431

June 21, 2007Big Stone County, Traverse County, Wilkin County, Minnesota; 19 counties in North Dakota; 26 counties in South Dakota

The Storm Prediction Center issued this severe thunderstorm watch at Jun 21, 2007, 2:29 AM CDT for Big Stone County, Traverse County, Wilkin County, Minnesota; 19 counties in North Dakota; 26 counties in South Dakota. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued: Jun 21, 2007, 2:29 AM CDT (07:29 UTC)
Expired: Jun 21, 2007, 10:00 AM CDT
In force: 8 hr
Issued by: the Storm Prediction Center
Largest hail expected: 2 in
Strongest gust expected: 60 kt

All 48 counties

Big Stone County, MN, Traverse County, MN, Wilkin County, MN, Adams County, ND, Bowman County, ND, Burleigh County, ND, Dickey County, ND, Emmons County, ND, Grant County, ND, Hettinger County, ND, Kidder County, ND, LaMoure County, ND, Logan County, ND, McIntosh County, ND, Morton County, ND, Oliver County, ND, Ransom County, ND, Richland County, ND, Sargent County, ND, Sioux County, ND, Slope County, ND, Stark County, ND, Brown County, SD, Buffalo County, SD, Campbell County, SD, Clark County, SD, Codington County, SD, Corson County, SD, Day County, SD, Deuel County, SD, Dewey County, SD, Edmunds County, SD, Faulk County, SD, Grant County, SD, Hamlin County, SD, Hand County, SD, Harding County, SD, Hughes County, SD, Hyde County, SD, Marshall County, SD, McPherson County, SD, Perkins County, SD, Potter County, SD, Roberts County, SD, Spink County, SD, Sully County, SD, Walworth County, SD, Ziebach County, SD

The radar

The Bismarck radar (KBIS), 74 km from the middle of the area, began a volume at 07:29 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes: 10%
One or more EF2 to EF5 tornadoes: 5%
Ten or more severe wind reports: 30%
One or more gusts of 65 knots or more: 20%
Ten or more severe hail reports: 70%
One or more hailstones of 2 inches or more: 20%
Six or more combined severe hail and wind reports: 90%

Warnings issued inside it

27 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

Issued	Product	Office	Counties	Lasted
Jun 21, 2:44 AM CDT	Severe Thunderstorm Warning	ABR	Edmunds, McPherson, Walworth	46 min
Jun 21, 2:47 AM CDT	Severe Thunderstorm Warning	ABR	McPherson	43 min
Jun 21, 3:03 AM CDT	Severe Thunderstorm Warning	BIS	Adams, Grant	57 min
Jun 21, 3:23 AM CDT	Severe Thunderstorm Warning	BIS	Slope	67 min
Jun 21, 3:25 AM CDT	Severe Thunderstorm Warning	ABR	McPherson	38 min
Jun 21, 3:29 AM CDT	Severe Thunderstorm Warning	ABR	Edmunds	61 min
Jun 21, 3:52 AM CDT	Tornado Warning	ABR	Edmunds	23 min
Jun 21, 4:03 AM CDT	Severe Thunderstorm Warning	BIS	Dickey	34 min
Jun 21, 4:19 AM CDT	Severe Thunderstorm Warning	BIS	Emmons	56 min
Jun 21, 4:22 AM CDT	Severe Thunderstorm Warning	ABR	Campbell, Edmunds, McPherson, Walworth	53 min
Jun 21, 4:26 AM CDT	Severe Thunderstorm Warning	BIS	Hettinger	64 min
Jun 21, 4:33 AM CDT	Severe Thunderstorm Warning	BIS	Sioux	57 min
Jun 21, 4:38 AM CDT	Severe Thunderstorm Warning	ABR	Corson	67 min
Jun 21, 5:05 AM CDT	Severe Thunderstorm Warning	ABR	Dewey, Potter, Walworth	55 min
Jun 21, 5:45 AM CDT	Severe Thunderstorm Warning	ABR	Corson	60 min
Jun 21, 5:52 AM CDT	Severe Thunderstorm Warning	ABR	Potter, Walworth	38 min
Jun 21, 6:18 AM CDT	Tornado Warning	ABR	Dewey, Potter	27 min
Jun 21, 6:35 AM CDT	Severe Thunderstorm Warning	ABR	Dewey	55 min
Jun 21, 6:43 AM CDT	Tornado Warning	ABR	Potter	32 min
Jun 21, 7:17 AM CDT	Severe Thunderstorm Warning	ABR	Dewey, Potter	58 min
Jun 21, 7:31 AM CDT	Severe Thunderstorm Warning	ABR	Dewey, Potter, Sully	59 min
Jun 21, 7:37 AM CDT	Tornado Warning	ABR	Sully	23 min
Jun 21, 7:57 AM CDT	Flash Flood Warning	ABR	Potter, Sully	3 hr
Jun 21, 8:27 AM CDT	Severe Thunderstorm Warning	ABR	Hughes, Hyde, Stanley, Sully	48 min
Jun 21, 8:59 AM CDT	Severe Thunderstorm Warning	ABR	Buffalo, Hand, Hyde	46 min
Jun 21, 9:19 AM CDT	Tornado Warning	ABR	Buffalo, Hand, Hyde	26 min
Jun 21, 9:41 AM CDT	Tornado Warning	ABR	Buffalo	34 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 7.5 hours before the alert went out and 240 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 833 J/kg
Mixed-layer CIN: -248 J/kg
Mixed-layer LCL: 1832 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 28 m²/s²
0-3 km storm-relative helicity: 115 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.2

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 20, 8:28 PM CDT	Mesoscale Discussion	SPC	Blue Earth, Dodge, Goodhue, Le Sueur, Olmsted, Rice and 2 more	92 min
Jun 20, 11:30 PM CDT	Mesoscale Discussion	SPC	Blue Earth, Dodge, Faribault, Fillmore, Freeborn, Goodhue and 7 more	90 min
Jun 21, 2:10 AM CDT	Mesoscale Discussion	SPC	Big Stone, Lac qui Parle, Stevens, Traverse, Yellow Medicine	95 min
Jun 21, 3:55 AM CDT	Mesoscale Discussion	SPC	Big Stone, Blue Earth, Brown, Carver, Chippewa, Cottonwood and 32 more	95 min
Jun 21, 4:27 AM CDT	Severe Thunderstorm Watch	SPC	Blue Earth, Brown, Carver, Chippewa, Dakota, Dodge and 33 more	8 hr
Jun 21, 7:14 AM CDT	Mesoscale Discussion	SPC	Blue Earth, Brown, Chippewa, Cottonwood, Faribault, Jackson and 11 more	91 min
Jun 21, 9:10 AM CDT	Mesoscale Discussion	SPC	Cottonwood, Jackson, Lincoln, Murray, Nobles, Pipestone and 1 more	35 min
Jun 21, 9:38 AM CDT	Severe Thunderstorm Watch	SPC	Cottonwood, Jackson, Lincoln, Lyon, Murray, Nobles and 2 more	6 hr
Jun 21, 11:08 AM CDT	Mesoscale Discussion	SPC	Anoka, Benton, Brown, Carver, Chippewa, Dakota and 25 more	67 min
Jun 21, 11:55 AM CDT	Mesoscale Discussion	SPC	Blue Earth, Carver, Dakota, Dodge, Faribault, Fillmore and 19 more	50 min
Jun 21, 11:59 AM CDT	Severe Thunderstorm Watch	SPC	Blue Earth, Brown, Carver, Dakota, Dodge, Faribault and 20 more	8 hr
Jun 21, 2:13 PM CDT	Mesoscale Discussion	SPC	Blue Earth, Brown, Carver, Cottonwood, Dakota, Dodge and 28 more	62 min
Jun 21, 3:15 PM CDT	Mesoscale Discussion	SPC	Cottonwood, Jackson, Lincoln, Lyon, Murray, Nobles and 2 more	30 min
Jun 21, 3:25 PM CDT	Mesoscale Discussion	SPC	Blue Earth, Brown, Carver, Dakota, Dodge, Faribault and 20 more	35 min
Jun 21, 5:42 PM CDT	Mesoscale Discussion	SPC	Houston	93 min
Jun 21, 5:34 AM CDT	Mesoscale Discussion	SPC	Adams, Dickey, Emmons, Grant, Hettinger, McIntosh and 3 more	86 min
Jun 21, 2:43 PM CDT	Mesoscale Discussion	SPC	Adams, Billings, Bowman, Golden Valley, Grant, Hettinger and 3 more	92 min
Jun 21, 4:37 PM CDT	Tornado Watch	SPC	Bennett, Butte, Custer, Dewey, Fall River, Haakon and 12 more	7 hr

Nearby

Severe Thunderstorm Watches in South Dakota, 2007 Severe Thunderstorm Watches in North Dakota, 2007 Severe Thunderstorm Watches in Minnesota, 2007 Every severe thunderstorm watch in 2007

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.