Alert archive / Iowa / Severe Thunderstorm Watches in 2007

Severe Thunderstorm Watch 434

June 21, 200742 counties in Iowa; 26 counties in Minnesota; 8 counties in Wisconsin

The Storm Prediction Center issued this severe thunderstorm watch at Jun 21, 2007, 11:59 AM CDT for 42 counties in Iowa; 26 counties in Minnesota; 8 counties in Wisconsin. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued: Jun 21, 2007, 11:59 AM CDT (16:59 UTC)
Expired: Jun 21, 2007, 8:00 PM CDT
In force: 8 hr
Issued by: the Storm Prediction Center
Largest hail expected: 3 in
Strongest gust expected: 60 kt

All 76 counties

Allamakee County, IA, Benton County, IA, Black Hawk County, IA, Boone County, IA, Bremer County, IA, Buchanan County, IA, Butler County, IA, Calhoun County, IA, Carroll County, IA, Cerro Gordo County, IA, Chickasaw County, IA, Clayton County, IA, Crawford County, IA, Delaware County, IA, Dubuque County, IA, Emmet County, IA, Fayette County, IA, Floyd County, IA, Franklin County, IA, Greene County, IA, Grundy County, IA, Hamilton County, IA, Hancock County, IA, Hardin County, IA, Howard County, IA, Humboldt County, IA, Jackson County, IA, Jones County, IA, Kossuth County, IA, Linn County, IA, Marshall County, IA, Mitchell County, IA, Palo Alto County, IA, Pocahontas County, IA, Sac County, IA, Story County, IA, Tama County, IA, Webster County, IA, Winnebago County, IA, Winneshiek County, IA, Worth County, IA, Wright County, IA, Blue Earth County, MN, Brown County, MN, Carver County, MN, Dakota County, MN, Dodge County, MN, Faribault County, MN, Fillmore County, MN, Freeborn County, MN, Goodhue County, MN, Houston County, MN, Le Sueur County, MN, Martin County, MN, McLeod County, MN, Mower County, MN, Nicollet County, MN, Olmsted County, MN, Redwood County, MN, Renville County, MN, Rice County, MN, Scott County, MN, Sibley County, MN, Steele County, MN, Wabasha County, MN, Waseca County, MN, Watonwan County, MN, Winona County, MN, Buffalo County, WI, Crawford County, WI, Grant County, WI, La Crosse County, WI, Monroe County, WI, Richland County, WI, Trempealeau County, WI, Vernon County, WI

The radar

The Minneapolis radar (KMPX), 153 km from the middle of the area, began a volume at 16:58 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: 20%
One or more EF2 to EF5 tornadoes: 5%
Ten or more severe wind reports: 80%
One or more gusts of 65 knots or more: 40%
Ten or more severe hail reports: 80%
One or more hailstones of 2 inches or more: 50%
Six or more combined severe hail and wind reports: 95%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jun 21, 2:14 PM CDT	Severe Thunderstorm Warning	DMX	Kossuth	61 min
Jun 21, 2:16 PM CDT	Severe Thunderstorm Warning	DMX	Palo Alto	44 min
Jun 21, 2:40 PM CDT	Severe Thunderstorm Warning	DMX	Palo Alto, Pocahontas	50 min
Jun 21, 2:42 PM CDT	Severe Thunderstorm Warning	DMX	Hancock	48 min
Jun 21, 3:01 PM CDT	Severe Thunderstorm Warning	DMX	Cerro Gordo	59 min
Jun 21, 3:05 PM CDT	Severe Thunderstorm Warning	DMX	Humboldt, Wright	40 min
Jun 21, 3:07 PM CDT	Severe Thunderstorm Warning	DMX	Butler	53 min
Jun 21, 3:07 PM CDT	Severe Thunderstorm Warning	DMX	Carroll, Crawford	38 min
Jun 21, 3:15 PM CDT	Severe Thunderstorm Warning	MPX	Blue Earth, Brown, Nicollet	60 min
Jun 21, 3:23 PM CDT	Severe Thunderstorm Warning	DMX	Black Hawk	67 min
Jun 21, 3:24 PM CDT	Severe Thunderstorm Warning	MPX	Faribault	66 min
Jun 21, 3:36 PM CDT	Severe Thunderstorm Warning	DMX	Butler	39 min
Jun 21, 3:39 PM CDT	Tornado Warning	DMX	Humboldt, Wright	36 min
Jun 21, 3:52 PM CDT	Severe Thunderstorm Warning	DMX	Greene	38 min
Jun 21, 3:55 PM CDT	Tornado Warning	DMX	Butler	50 min
Jun 21, 4:05 PM CDT	Tornado Warning	MPX	Blue Earth	25 min
Jun 21, 4:09 PM CDT	Tornado Warning	DMX	Black Hawk	51 min
Jun 21, 4:11 PM CDT	Severe Thunderstorm Warning	DMX	Cerro Gordo, Worth	49 min
Jun 21, 4:13 PM CDT	Severe Thunderstorm Warning	DMX	Boone, Dallas	47 min
Jun 21, 4:14 PM CDT	Severe Thunderstorm Warning	DMX	Bremer	46 min
Jun 21, 4:19 PM CDT	Severe Thunderstorm Warning	DMX	Butler	29 min
Jun 21, 4:26 PM CDT	Severe Thunderstorm Warning	MPX	Martin	37 min
Jun 21, 4:27 PM CDT	Severe Thunderstorm Warning	MPX	Freeborn	63 min
Jun 21, 4:29 PM CDT	Tornado Warning	MPX	Blue Earth, Faribault	46 min
Jun 21, 4:31 PM CDT	Severe Thunderstorm Warning	DMX	Boone, Story	44 min
Jun 21, 4:32 PM CDT	Severe Thunderstorm Warning	ARX	Chickasaw, Floyd	58 min
Jun 21, 4:35 PM CDT	Severe Thunderstorm Warning	DMX	Hamilton	40 min
Jun 21, 4:35 PM CDT	Severe Thunderstorm Warning	ARX	Mower	55 min
Jun 21, 4:53 PM CDT	Tornado Warning	DMX	Story	37 min
Jun 21, 4:54 PM CDT	Severe Thunderstorm Warning	MPX	Carver, Scott, Sibley	66 min
Jun 21, 4:56 PM CDT	Severe Thunderstorm Warning	DMX	Polk, Story	49 min
Jun 21, 5:06 PM CDT	Severe Thunderstorm Warning	MPX	McLeod, Renville	39 min
Jun 21, 5:08 PM CDT	Severe Thunderstorm Warning	DMX	Hardin	36 min
Jun 21, 5:09 PM CDT	Severe Thunderstorm Warning	ARX	Chickasaw, Fayette, Winneshiek	66 min
Jun 21, 5:10 PM CDT	Severe Thunderstorm Warning	ARX	Olmsted	35 min
Jun 21, 5:10 PM CDT	Severe Thunderstorm Warning	MPX	Waseca	30 min
Jun 21, 5:15 PM CDT	Severe Thunderstorm Warning	MPX	Faribault	30 min
Jun 21, 5:16 PM CDT	Severe Thunderstorm Warning	DMX	Black Hawk	44 min
Jun 21, 5:24 PM CDT	Tornado Warning	DMX	Black Hawk	36 min
Jun 21, 5:26 PM CDT	Severe Thunderstorm Warning	MPX	Freeborn	23 min
Jun 21, 5:28 PM CDT	Severe Thunderstorm Warning	ARX	Howard, Mitchell	46 min
Jun 21, 5:33 PM CDT	Severe Thunderstorm Warning	MPX	Le Sueur	25 min
Jun 21, 5:37 PM CDT	Severe Thunderstorm Warning	MPX	McLeod, Renville	53 min
Jun 21, 5:46 PM CDT	Severe Thunderstorm Warning	ARX	Winona	29 min
Jun 21, 5:47 PM CDT	Severe Thunderstorm Warning	DVN	Benton, Buchanan	58 min
Jun 21, 6:00 PM CDT	Severe Thunderstorm Warning	MPX	Sibley	60 min
Jun 21, 6:10 PM CDT	Severe Thunderstorm Warning	ARX	Allamakee	51 min
Jun 21, 6:35 PM CDT	Severe Thunderstorm Warning	DVN	Linn	55 min
Jun 21, 6:38 PM CDT	Severe Thunderstorm Warning	MPX	Nicollet	43 min
Jun 21, 6:39 PM CDT	Severe Thunderstorm Warning	DVN	Benton	41 min
Jun 21, 6:46 PM CDT	Severe Thunderstorm Warning	MPX	Goodhue	29 min
Jun 21, 6:50 PM CDT	Severe Thunderstorm Warning	MPX	Brown	25 min
Jun 21, 6:59 PM CDT	Severe Thunderstorm Warning	MPX	Blue Earth	61 min
Jun 21, 7:12 PM CDT	Severe Thunderstorm Warning	MPX	Brown	33 min
Jun 21, 7:37 PM CDT	Severe Thunderstorm Warning	ARX	Dodge, Mower	53 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

Minneapolis, MN (KMPX), launched 12:00Z, 5.0 hours before the alert went out and 154 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2261 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: -101 m²/s²
0-3 km storm-relative helicity: 64 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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, 11:30 PM CDT	Mesoscale Discussion	SPC	Howard, Mitchell, Winnebago, Worth	90 min
Jun 21, 4:27 AM CDT	Severe Thunderstorm Watch	SPC	Allamakee, Howard, Mitchell, Winneshiek	8 hr
Jun 21, 9:10 AM CDT	Mesoscale Discussion	SPC	Clay, Dickinson, Lyon, O'Brien, Osceola, Sioux	35 min
Jun 21, 9:38 AM CDT	Severe Thunderstorm Watch	SPC	Buena Vista, Cherokee, Clay, Dickinson, Ida, Lyon and 5 more	6 hr
Jun 21, 9:57 AM CDT	Mesoscale Discussion	SPC	Allamakee, Cedar, Clayton, Clinton, Delaware, Des Moines and 10 more	33 min
Jun 21, 11:55 AM CDT	Mesoscale Discussion	SPC	Allamakee, Black Hawk, Bremer, Buchanan, Butler, Cerro Gordo and 16 more	50 min
Jun 21, 2:13 PM CDT	Mesoscale Discussion	SPC	Allamakee, Benton, Black Hawk, Boone, Bremer, Buchanan and 50 more	62 min
Jun 21, 3:15 PM CDT	Mesoscale Discussion	SPC	Cherokee, Clay, Dickinson, Ida, Lyon, O'Brien and 4 more	30 min
Jun 21, 3:25 PM CDT	Mesoscale Discussion	SPC	Adair, Allamakee, Audubon, Benton, Black Hawk, Boone and 52 more	35 min
Jun 21, 3:55 PM CDT	Severe Thunderstorm Watch	SPC	Adair, Adams, Audubon, Cass, Cedar, Clarke and 26 more	3 hr
Jun 21, 5:42 PM CDT	Mesoscale Discussion	SPC	Allamakee, Benton, Black Hawk, Bremer, Buchanan, Cedar and 25 more	93 min
Jun 21, 6:47 PM CDT	Severe Thunderstorm Watch	SPC	Appanoose, Cedar, Clayton, Clinton, Davis, Delaware and 18 more	4 hr
Jun 20, 8:28 PM CDT	Mesoscale Discussion	SPC	Blue Earth, Dodge, Goodhue, Le Sueur, Olmsted, Rice and 2 more	92 min
Jun 21, 2:10 AM CDT	Mesoscale Discussion	SPC	Big Stone, Lac qui Parle, Stevens, Traverse, Yellow Medicine	95 min
Jun 21, 2:29 AM CDT	Severe Thunderstorm Watch	SPC	Big Stone, Traverse, Wilkin	8 hr
Jun 21, 3:55 AM CDT	Mesoscale Discussion	SPC	Big Stone, Blue Earth, Brown, Carver, Chippewa, Cottonwood and 32 more	95 min
Jun 21, 7:14 AM CDT	Mesoscale Discussion	SPC	Blue Earth, Brown, Chippewa, Cottonwood, Faribault, Jackson and 11 more	91 min
Jun 21, 11:08 AM CDT	Mesoscale Discussion	SPC	Anoka, Benton, Brown, Carver, Chippewa, Dakota and 25 more	67 min
Jun 20, 7:25 PM CDT	Mesoscale Discussion	SPC	Adams, Barron, Buffalo, Chippewa, Clark, Dunn and 18 more	95 min
Jun 21, 12:27 PM CDT	Mesoscale Discussion	SPC	Columbia, Dane, Dodge, Green, Iowa, Jefferson and 4 more	63 min

Nearby

Severe Thunderstorm Watches in Iowa, 2007 Severe Thunderstorm Watches in Minnesota, 2007 Severe Thunderstorm Watches in Wisconsin, 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.