Alert archive / Iowa / Severe Thunderstorm Watches in 2014

Severe Thunderstorm Watch 320

June 18, 201422 counties in Iowa; 7 counties in Minnesota; 9 counties in Wisconsin

The Storm Prediction Center issued this severe thunderstorm watch at Jun 18, 2014, 3:47 AM CDT for 22 counties in Iowa; 7 counties in Minnesota; 9 counties in Wisconsin. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Jun 18, 2014, 3:47 AM CDT (08:47 UTC)
Expired
Jun 18, 2014, 7:45 AM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 38 counties

Allamakee County, IA, Black Hawk County, IA, Bremer County, IA, Butler County, IA, Calhoun County, IA, Cerro Gordo County, IA, Chickasaw County, IA, Clayton County, IA, Fayette County, IA, Floyd County, IA, Franklin County, IA, Grundy County, IA, Hamilton County, IA, Hardin County, IA, Howard County, IA, Humboldt County, IA, Mitchell County, IA, Pocahontas County, IA, Webster County, IA, Winneshiek County, IA, Worth County, IA, Wright County, IA, Dodge County, MN, Fillmore County, MN, Houston County, MN, Mower County, MN, Olmsted County, MN, Wabasha County, MN, Winona County, MN, Buffalo County, WI, Crawford County, WI, Grant County, WI, Jackson County, WI, La Crosse County, WI, Monroe County, WI, Richland County, WI, Trempealeau County, WI, Vernon County, WI

The radar

The La Crosse radar (KARX), 99 km from the middle of the area, began a volume at 08:47 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
2%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
5%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jun 18, 4:01 AM CDTFlash Flood WarningARXAdams, Clark, Jackson, Juneau6 hr
Jun 18, 5:06 AM CDTFlash Flood WarningDMXHumboldt, Wright6 hr
Jun 18, 6:01 AM CDTFlash Flood WarningARXJackson, Trempealeau4 hr
Jun 18, 6:25 AM CDTSevere Thunderstorm WarningARXAdams, Juneau, Monroe, Richland, Vernon65 min
Jun 18, 6:43 AM CDTFlash Flood WarningARXMonroe3 hr
Jun 18, 7:05 AM CDTSevere Thunderstorm WarningARXGrant40 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, 8.8 hours before the alert went out and 180 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, Minneapolis, MN at 00:00Z on 2014-06-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 901 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, Minneapolis, MN at 00:00Z on 2014-06-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -31 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
901 J/kg
Mixed-layer CIN
-172 J/kg
Mixed-layer LCL
1176 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
-31 m²/s²
0-3 km storm-relative helicity
71 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.6

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 17, 7:44 PM CDTMesoscale DiscussionSPCAllamakee, Howard, Winneshiek2 hr
Jun 17, 9:38 PM CDTMesoscale DiscussionSPCClinton, Jackson97 min
Jun 17, 10:13 PM CDTSevere Thunderstorm WatchSPCAllamakee, Buchanan, Chickasaw, Clayton, Clinton, Delaware and 8 more6 hr
Jun 17, 10:18 PM CDTMesoscale DiscussionSPCCherokee, Clay, Dickinson, Ida, Lyon, O'Brien and 4 more57 min
Jun 17, 11:01 PM CDTMesoscale DiscussionSPCPlymouth, Sioux29 min
Jun 17, 11:23 PM CDTMesoscale DiscussionSPCBuena Vista, Cherokee, Clay, Dickinson, Emmet, Hancock and 11 more37 min
Jun 17, 11:39 PM CDTTornado WatchSPCBlack Hawk, Bremer, Buena Vista, Butler, Calhoun, Cerro Gordo and 25 more5 hr
Jun 18, 1:52 AM CDTMesoscale DiscussionSPCBoone, Buena Vista, Calhoun, Carroll, Cerro Gordo, Cherokee and 27 more83 min
Jun 18, 3:07 AM CDTMesoscale DiscussionSPCAllamakee, Black Hawk, Bremer, Buchanan, Butler, Chickasaw and 11 more53 min
Jun 18, 5:36 AM CDTMesoscale DiscussionSPCAllamakee, Black Hawk, Bremer, Buchanan, Butler, Clayton and 12 more54 min
Jun 18, 3:29 PM CDTMesoscale DiscussionSPCLyon, Plymouth, Sioux91 min
Jun 18, 6:23 PM CDTTornado WatchSPCLyon, Plymouth, Sioux, Woodbury5 hr
Jun 17, 10:36 PM CDTMesoscale DiscussionSPCAnoka, Blue Earth, Brown, Carver, Chisago, Dakota and 16 more84 min
Jun 18, 12:59 AM CDTMesoscale DiscussionSPCAdams, Brown, Calumet, Columbia, Dane, Dodge and 30 more91 min

Nearby

Severe Thunderstorm Watches in Iowa, 2014Severe Thunderstorm Watches in Wisconsin, 2014Severe Thunderstorm Watches in Minnesota, 2014Every severe thunderstorm watch in 2014

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.