Alert archive / Wisconsin / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 677

July 23, 2011Allamakee County, Howard County, Winneshiek County, Iowa; 7 counties in Minnesota; 10 counties in Wisconsin

The Storm Prediction Center issued this severe thunderstorm watch at Jul 23, 2011, 10:14 AM CDT for Allamakee County, Howard County, Winneshiek County, Iowa; 7 counties in Minnesota; 10 counties in Wisconsin. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Jul 23, 2011, 10:14 AM CDT (15:14 UTC)
Expired
Jul 23, 2011, 2:00 PM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt

Counties Allamakee County, IA, Howard County, IA, Winneshiek County, IA, Dodge County, MN, Fillmore County, MN, Houston County, MN, Mower County, MN, Olmsted County, MN, Wabasha County, MN, Winona County, MN, Adams County, WI, Buffalo County, WI, Crawford 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 La Crosse radar (KARX), 37 km from the middle of the area, began a volume at 15:14 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
50%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jul 23, 11:03 AM CDTSevere Thunderstorm WarningARXFillmore, Olmsted, Winona42 min
Jul 23, 11:38 AM CDTSevere Thunderstorm WarningARXHouston, Winona52 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, 3.2 hours before the alert went out and 195 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 12:00Z on 2011-07-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1467 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 12:00Z on 2011-07-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 36 square meters per square second.19395878Sfc1 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
1467 J/kg
Mixed-layer CIN
-142 J/kg
Mixed-layer LCL
875 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
36 m²/s²
0-3 km storm-relative helicity
175 m²/s²
Significant tornado parameter
0.2
Supercell composite
4.2

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 22, 7:38 PM CDTMesoscale DiscussionSPCBenton, Black Hawk, Bremer, Buchanan, Butler, Cedar and 19 more97 min
Jul 23, 1:10 PM CDTMesoscale DiscussionSPCAllamakee, Winneshiek65 min
Jul 23, 1:52 PM CDTMesoscale DiscussionSPCClay, Dickinson, Emmet, Hancock, Kossuth, Lyon and 6 more83 min
Jul 23, 4:57 PM CDTMesoscale DiscussionSPCAdair, Adams, Appanoose, Cass, Clarke, Dallas and 26 more93 min
Jul 23, 5:16 PM CDTSevere Thunderstorm WatchSPCAdair, Adams, Appanoose, Cass, Clarke, Davis and 25 more4 hr
Jul 22, 10:11 PM CDTMesoscale DiscussionSPCBecker, Clay, Grant, Norman, Otter Tail, Wilkin64 min
Jul 22, 10:15 PM CDTSevere Thunderstorm WatchSPCBecker, Clay, Clearwater, Grant, Hubbard, Mahnomen and 6 more7 hr
Jul 23, 1:25 AM CDTMesoscale DiscussionSPCBecker, Big Stone, Clay, Clearwater, Douglas, Grant and 13 more35 min
Jul 23, 1:41 AM CDTSevere Thunderstorm WatchSPCBecker, Benton, Big Stone, Chippewa, Douglas, Grant and 20 more5 hr
Jul 23, 4:38 AM CDTMesoscale DiscussionSPCAitkin, Anoka, Becker, Benton, Big Stone, Carver and 36 more67 min
Jul 23, 9:37 AM CDTMesoscale DiscussionSPCFillmore, Houston, Olmsted, Wabasha, Winona53 min
Jul 23, 5:26 PM CDTMesoscale DiscussionSPCAdams, Clark, Eau Claire, Jackson, Juneau, Marathon and 9 more64 min
Jul 23, 6:36 PM CDTSevere Thunderstorm WatchSPCAdams, Clark, Columbia, Dane, Dodge, Fond du Lac and 19 more7 hr

Nearby

Severe Thunderstorm Watches in Wisconsin, 2011Severe Thunderstorm Watches in Minnesota, 2011Severe Thunderstorm Watches in Iowa, 2011Every 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.