Alert archive / Iowa / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 620

July 10, 201119 counties in Iowa; 12 counties in Minnesota; 12 counties in Wisconsin

The Storm Prediction Center issued this severe thunderstorm watch at Jul 10, 2011, 10:10 PM CDT for 19 counties in Iowa; 12 counties in Minnesota; 12 counties in Wisconsin. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Jul 10, 2011, 10:10 PM CDT (03:10 UTC)
Expired: Jul 11, 2011, 4:07 AM CDT
In force: 6 hr
Issued by: the Storm Prediction Center
Largest hail expected: 1.5 in
Strongest gust expected: 60 kt

All 43 counties

Allamakee County, IA, Black Hawk County, IA, Bremer County, IA, Butler County, IA, Cerro Gordo County, IA, Chickasaw County, IA, Clayton County, IA, Emmet County, IA, Fayette County, IA, Floyd County, IA, Franklin County, IA, Grundy County, IA, Hancock County, IA, Howard County, IA, Kossuth County, IA, Mitchell County, IA, Winnebago County, IA, Winneshiek County, IA, Worth County, IA, Dodge County, MN, Faribault County, MN, Fillmore County, MN, Freeborn County, MN, Goodhue County, MN, Houston County, MN, Martin County, MN, Mower County, MN, Olmsted County, MN, Steele County, MN, Wabasha County, MN, Winona County, MN, Barron County, WI, Buffalo County, WI, Chippewa County, WI, Dunn County, WI, Eau Claire County, WI, La Crosse County, WI, Pepin County, WI, Pierce County, WI, Polk County, WI, Rusk County, WI, Saint Croix County, WI, Trempealeau County, WI

The radar

The La Crosse radar (KARX), 134 km from the middle of the area, began a volume at 03:13 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: 40%
One or more gusts of 65 knots or more: 30%
Ten or more severe hail reports: 30%
One or more hailstones of 2 inches or more: 20%
Six or more combined severe hail and wind reports: 70%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jul 10, 10:48 PM CDT	Severe Thunderstorm Warning	MPX	Blue Earth, Carver, Le Sueur, Rice, Scott, Steele and 1 more	57 min
Jul 10, 11:13 PM CDT	Severe Thunderstorm Warning	MPX	Dakota, Goodhue, Rice, Steele	47 min
Jul 10, 11:39 PM CDT	Severe Thunderstorm Warning	MPX	Dakota, Goodhue	51 min
Jul 10, 11:45 PM CDT	Severe Thunderstorm Warning	MPX	Dunn, Saint Croix	60 min
Jul 10, 11:46 PM CDT	Severe Thunderstorm Warning	ARX	Dodge, Olmsted, Wabasha	59 min
Jul 11, 12:12 AM CDT	Severe Thunderstorm Warning	MPX	Pepin, Pierce	52 min
Jul 11, 12:23 AM CDT	Severe Thunderstorm Warning	ARX	Wabasha	37 min
Jul 11, 1:12 AM CDT	Severe Thunderstorm Warning	DMX	Emmet, Kossuth, Palo Alto	48 min
Jul 11, 2:11 AM CDT	Severe Thunderstorm Warning	MPX	Faribault, Freeborn	64 min
Jul 11, 2:24 AM CDT	Severe Thunderstorm Warning	DMX	Cerro Gordo, Hancock, Winnebago, Worth	51 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 00:00Z, 3.2 hours before the alert went out and 138 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: 1401 J/kg
Mixed-layer CIN: -78 J/kg
Mixed-layer LCL: 1316 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 13 m²/s²
0-3 km storm-relative helicity: 15 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
Jul 10, 7:51 PM CDT	Mesoscale Discussion	SPC	Allamakee, Howard, Mitchell, Winneshiek	84 min
Jul 10, 9:53 PM CDT	Mesoscale Discussion	SPC	Allamakee, Cerro Gordo, Chickasaw, Dickinson, Emmet, Floyd and 9 more	67 min
Jul 10, 10:27 PM CDT	Mesoscale Discussion	SPC	Cherokee, Harrison, Monona, Plymouth, Sioux, Woodbury	63 min
Jul 10, 10:57 PM CDT	Severe Thunderstorm Watch	SPC	Harrison, Mills, Monona, Montgomery, Pottawattamie, Shelby	4 hr
Jul 10, 11:45 PM CDT	Mesoscale Discussion	SPC	Allamakee, Bremer, Cerro Gordo, Chickasaw, Clayton, Delaware and 8 more	90 min
Jul 10, 11:56 PM CDT	Severe Thunderstorm Watch	SPC	Buena Vista, Cherokee, Clay, Dickinson, Ida, Lyon and 5 more	4 hr
Jul 11, 1:08 AM CDT	Severe Thunderstorm Watch	SPC	Adair, Adams, Audubon, Black Hawk, Boone, Bremer and 38 more	13 min
Jul 11, 1:21 AM CDT	Severe Thunderstorm Watch	SPC	Adair, Adams, Audubon, Black Hawk, Boone, Bremer and 38 more	4 hr
Jul 11, 2:36 AM CDT	Mesoscale Discussion	SPC	Adair, Adams, Benton, Black Hawk, Boone, Bremer and 52 more	114 min
Jul 11, 3:30 AM CDT	Severe Thunderstorm Watch	SPC	Allamakee, Benton, Buchanan, Cedar, Chickasaw, Clayton and 18 more	6 hr
Jul 11, 5:07 AM CDT	Mesoscale Discussion	SPC	Benton, Black Hawk, Buchanan, Cedar, Clayton, Clinton and 15 more	113 min
Jul 11, 2:07 AM CDT	Mesoscale Discussion	SPC	Adams, Brown, Calumet, Clark, Columbia, Dodge and 27 more	83 min
Jul 11, 7:10 AM CDT	Mesoscale Discussion	SPC	Dane, Green, Jefferson, Kenosha, Milwaukee, Racine and 3 more	95 min
Jul 11, 7:50 AM CDT	Mesoscale Discussion	SPC	Kenosha	55 min

Nearby

Severe Thunderstorm Watches in Iowa, 2011 Severe Thunderstorm Watches in Minnesota, 2011 Severe Thunderstorm Watches in Wisconsin, 2011 Every severe thunderstorm watch in 2011

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.