Alert archive / Wisconsin / Tornado Watches in 2011

Tornado Watch 532

June 21, 201113 counties in Minnesota; 28 counties in Wisconsin

The Storm Prediction Center issued this tornado watch at Jun 21, 2011, 2:11 PM CDT for 13 counties in Minnesota; 28 counties in Wisconsin. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Jun 21, 2011, 2:11 PM CDT (19:11 UTC)
Expired
Jun 21, 2011, 9:00 PM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 41 counties

Anoka County, MN, Chisago County, MN, Dakota County, MN, Goodhue County, MN, Hennepin County, MN, Houston County, MN, Isanti County, MN, Ramsey County, MN, Sherburne County, MN, Wabasha County, MN, Washington County, MN, Winona County, MN, Wright County, MN, Adams County, WI, Barron County, WI, Buffalo County, WI, Chippewa County, WI, Clark County, WI, Columbia County, WI, Dane County, WI, Dodge County, WI, Dunn County, WI, Eau Claire County, WI, Green Lake County, WI, Iowa County, WI, Jackson County, WI, Jefferson County, WI, Juneau County, WI, La Crosse County, WI, Marquette County, WI, Monroe County, WI, Pepin County, WI, Pierce County, WI, Polk County, WI, Richland County, WI, Rusk County, WI, Saint Croix County, WI, Sauk County, WI, Taylor County, WI, Trempealeau County, WI, Vernon County, WI

The radar

The La Crosse radar (KARX), 90 km from the middle of the area, began a volume at 19:10 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
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
50%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jun 21, 2:21 PM CDTTornado WarningMPXDakota, Washington24 min
Jun 21, 2:42 PM CDTSevere Thunderstorm WarningMKXDodge, Jefferson, Walworth, Washington, Waukesha33 min
Jun 21, 2:45 PM CDTTornado WarningMKXMarquette30 min
Jun 21, 3:06 PM CDTTornado WarningMKXGreen Lake, Marquette24 min
Jun 21, 3:09 PM CDTTornado WarningARXWabasha48 min
Jun 21, 3:10 PM CDTSevere Thunderstorm WarningMKXDodge, Milwaukee, Ozaukee, Washington, Waukesha50 min
Jun 21, 3:13 PM CDTTornado WarningMPXAnoka, Hennepin, Ramsey32 min
Jun 21, 3:14 PM CDTTornado WarningMKXDodge, Fond du Lac, Green Lake31 min
Jun 21, 3:27 PM CDTTornado WarningMKXGreen Lake, Marquette33 min
Jun 21, 3:44 PM CDTTornado WarningMKXFond du Lac, Green Lake31 min
Jun 21, 3:59 PM CDTTornado WarningMKXGreen Lake31 min
Jun 21, 7:20 PM CDTSevere Thunderstorm WarningMKXDane16 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, 7.2 hours before the alert went out and 149 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 2011-06-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2011-06-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 316 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
629 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
316 m²/s²
0-3 km storm-relative helicity
260 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

054 
WWUS20 KWNS 211911
SEL2
SPC WW 211911
MNZ000-WIZ000-220200-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 532
NWS STORM PREDICTION CENTER NORMAN OK
215 PM CDT TUE JUN 21 2011

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

       PARTS OF SOUTHEASTERN MINNESOTA
       PARTS OF SOUTHERN AND WESTERN WISCONSIN

EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 215 PM UNTIL
900 PM CDT.

TORNADOES...HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 75 STATUTE
MILES EAST AND WEST OF A LINE FROM 55 MILES NORTH NORTHEAST OF
MINNEAPOLIS MINNESOTA TO 20 MILES SOUTH SOUTHWEST OF MADISON
WISCONSIN.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU2).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

OTHER WATCH INFORMATION...CONTINUE...WW 531...

DISCUSSION...BANDS OF THUNDERSTORMS WILL ROTATE ACROSS THE WATCH AS
THE UPPER LOW OVER NWRN IA MOVES SLOWLY E.  LOW LEVEL SHEAR
ENVIRONMENT VERY FAVORABLE FOR LOW TOPPED SUPERCELLS. TORNADOES WILL
BE POSSIBLE WITH ANY SUPERCELLS AS ACTIVITY SLOWLY MOVES E ACROSS
THE WATCH.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
400. MEAN STORM MOTION VECTOR 18030.


...HALES

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 20, 7:46 PM CDTMesoscale DiscussionSPCAdair, Adams, Audubon, Carroll, Cass, Crawford and 12 more59 min
Jun 20, 9:02 PM CDTMesoscale DiscussionSPCAudubon, Boone, Buena Vista, Calhoun, Carroll, Cherokee and 21 more58 min
Jun 20, 10:22 PM CDTMesoscale DiscussionSPCAppanoose, Benton, Black Hawk, Boone, Bremer, Buchanan and 48 more83 min
Jun 20, 10:58 PM CDTTornado WatchSPCAppanoose, Black Hawk, Bremer, Butler, Cerro Gordo, Davis and 17 more4 hr
Jun 21, 1:25 AM CDTMesoscale DiscussionSPCBenton, Black Hawk, Bremer, Buchanan, Butler, Chickasaw and 14 more35 min
Jun 21, 11:45 AM CDTMesoscale DiscussionSPCAllamakee, Clayton, Clinton, Delaware, Dubuque, Fayette and 5 more3 hr
Jun 21, 5:42 PM CDTSevere Thunderstorm WatchSPCGreen, Kenosha, Milwaukee, Racine, Rock, Walworth and 1 more4 hr

Nearby

Tornado Watches in Wisconsin, 2011Tornado Watches in Minnesota, 2011Every tornado 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.