Alert archive / Iowa / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 519

July 25, 201254 counties in Iowa; 17 counties in Minnesota; 11 counties in Wisconsin

The Storm Prediction Center issued this severe thunderstorm watch at Jul 25, 2012, 5:16 PM CDT for 54 counties in Iowa; 17 counties in Minnesota; 11 counties in Wisconsin. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Jul 25, 2012, 5:16 PM CDT (22:16 UTC)
Expired
Jul 26, 2012, 1:00 AM CDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 82 counties

Adair County, IA, Adams County, IA, Allamakee County, IA, Audubon County, IA, Black Hawk County, IA, Boone County, IA, Bremer County, IA, Buena Vista County, IA, Butler County, IA, Calhoun County, IA, Carroll County, IA, Cass County, IA, Cerro Gordo County, IA, Cherokee County, IA, Chickasaw County, IA, Clay County, IA, Clayton County, IA, Crawford County, IA, Dallas County, IA, Dickinson County, IA, Emmet County, IA, Fayette County, IA, Floyd County, IA, Franklin County, IA, Greene County, IA, Grundy County, IA, Guthrie County, IA, Hamilton County, IA, Hancock County, IA, Hardin County, IA, Howard County, IA, Humboldt County, IA, Ida County, IA, Jasper County, IA, Kossuth County, IA, Madison County, IA, Marshall County, IA, Mitchell County, IA, O'Brien County, IA, Palo Alto County, IA, Pocahontas County, IA, Polk County, IA, Poweshiek County, IA, Sac County, IA, Story County, IA, Tama County, IA, Taylor County, IA, Union County, IA, Webster County, IA, Winnebago County, IA, Winneshiek County, IA, Woodbury County, IA, Worth County, IA, Wright County, IA, Blue Earth County, MN, Dodge County, MN, Faribault County, MN, Fillmore County, MN, Freeborn County, MN, Goodhue County, MN, Houston County, MN, Jackson County, MN, Martin County, MN, Mower County, MN, Olmsted County, MN, Rice County, MN, Steele County, MN, Wabasha County, MN, Waseca County, MN, Watonwan County, MN, Winona County, MN, Adams County, WI, Buffalo County, WI, Crawford County, WI, Grant County, WI, Jackson County, WI, Juneau County, WI, La Crosse County, WI, Monroe County, WI, Richland County, WI, Trempealeau County, WI, Vernon County, WI

The radar

The Des Moines radar (KDMX), 135 km from the middle of the area, began a volume at 22:18 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
50%
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

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

IssuedProductOfficeCountiesLasted
Jul 25, 5:16 PM CDTSevere Thunderstorm WarningFSDWoodbury29 min
Jul 25, 5:25 PM CDTSevere Thunderstorm WarningFSDCherokee, O'Brien35 min
Jul 25, 5:31 PM CDTSevere Thunderstorm WarningFSDWoodbury59 min
Jul 25, 5:43 PM CDTSevere Thunderstorm WarningFSDWoodbury47 min
Jul 25, 6:03 PM CDTSevere Thunderstorm WarningFSDClay, Dickinson42 min
Jul 25, 6:08 PM CDTSevere Thunderstorm WarningDMXEmmet, Palo Alto52 min
Jul 25, 6:17 PM CDTSevere Thunderstorm WarningDMXEmmet, Kossuth, Palo Alto43 min
Jul 25, 6:38 PM CDTSevere Thunderstorm WarningDMXPalo Alto52 min
Jul 25, 6:58 PM CDTSevere Thunderstorm WarningDMXKossuth47 min
Jul 25, 7:09 PM CDTSevere Thunderstorm WarningDMXHumboldt, Pocahontas51 min
Jul 25, 7:23 PM CDTSevere Thunderstorm WarningDMXCalhoun, Carroll, Greene, Sac37 min
Jul 25, 7:29 PM CDTSevere Thunderstorm WarningDMXHancock, Wright46 min
Jul 25, 8:02 PM CDTSevere Thunderstorm WarningDMXBoone, Calhoun, Greene, Hamilton, Webster43 min
Jul 25, 8:09 PM CDTSevere Thunderstorm WarningDMXCerro Gordo, Franklin, Hamilton, Hancock, Hardin, Wright51 min
Jul 25, 8:22 PM CDTSevere Thunderstorm WarningDMXMarshall53 min
Jul 25, 8:38 PM CDTSevere Thunderstorm WarningARXClayton22 min
Jul 25, 8:39 PM CDTSevere Thunderstorm WarningDMXBoone, Hamilton, Hardin, Story, Webster66 min
Jul 25, 9:03 PM CDTSevere Thunderstorm WarningARXGrant57 min
Jul 25, 9:04 PM CDTSevere Thunderstorm WarningDMXJasper, Marion, Polk, Story, Warren41 min
Jul 25, 9:10 PM CDTSevere Thunderstorm WarningDMXGrundy, Hardin, Marshall, Story, Tama50 min
Jul 25, 9:40 PM CDTSevere Thunderstorm WarningARXChickasaw35 min
Jul 25, 9:52 PM CDTSevere Thunderstorm WarningDMXBlack Hawk33 min
Jul 25, 9:57 PM CDTSevere Thunderstorm WarningDMXPoweshiek, Tama34 min
Jul 25, 10:03 PM CDTSevere Thunderstorm WarningARXFayette, Winneshiek43 min
Jul 25, 10:25 PM CDTSevere Thunderstorm WarningARXClayton65 min
Jul 25, 10:49 PM CDTSevere Thunderstorm WarningARXGrant56 min
Jul 25, 11:45 PM CDTSevere Thunderstorm WarningARXRichland30 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

Omaha, NE (KOAX), launched 12:00Z, 10.3 hours before the alert went out and 218 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-pSkew-T log-p diagram, Omaha, NE at 12:00Z on 2012-07-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 675 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 12:00Z on 2012-07-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 198 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
675 J/kg
Mixed-layer CIN
-402 J/kg
Mixed-layer LCL
2150 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
198 m²/s²
0-3 km storm-relative helicity
222 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 25, 4:28 PM CDTSevere Thunderstorm WatchSPCFremont, Harrison, Mills, Monona, Montgomery, Page and 2 more7 hr
Jul 24, 9:08 PM CDTSevere Thunderstorm WatchSPCBecker, Cass, Clay, Crow Wing, Douglas, Grant and 8 more7 hr
Jul 24, 11:24 PM CDTMesoscale DiscussionSPCAitkin, Becker, Benton, Big Stone, Cass, Clay and 20 more96 min
Jul 25, 2:05 AM CDTMesoscale DiscussionSPCAitkin, Carlton, Cass, Crow Wing, Pine55 min
Jul 25, 2:24 AM CDTSevere Thunderstorm WatchSPCAitkin, Benton, Carlton, Cass, Chisago, Crow Wing and 13 more5 hr
Jul 25, 3:41 AM CDTMesoscale DiscussionSPCBecker, Clay, Grant, Hubbard, Mahnomen, Otter Tail and 2 more34 min
Jul 25, 5:24 AM CDTMesoscale DiscussionSPCAitkin, Benton, Big Stone, Carlton, Cass, Chisago and 20 more66 min
Jul 25, 1:56 PM CDTMesoscale DiscussionSPCBecker, Beltrami, Big Stone, Clay, Clearwater, Grant and 14 more2 hr
Jul 25, 2:52 PM CDTMesoscale DiscussionSPCAdams, Antelope, Boone, Buffalo, Butler, Cedar and 42 more113 min
Jul 25, 2:57 PM CDTMesoscale DiscussionSPCBrown, Calumet, Clark, Eau Claire, Fond du Lac, Jackson and 17 more2 hr
Jul 25, 6:25 PM CDTMesoscale DiscussionSPCBrown, Calumet, Dodge, Fond du Lac, Green Lake, Kewaunee and 8 more95 min
Jul 25, 6:38 PM CDTSevere Thunderstorm WatchSPCBrown, Calumet, Columbia, Dane, Dodge, Fond du Lac and 23 more7 hr

Nearby

Severe Thunderstorm Watches in Iowa, 2012Severe Thunderstorm Watches in Minnesota, 2012Severe Thunderstorm Watches in Wisconsin, 2012Every severe thunderstorm watch in 2012

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.