Alert archive / Wisconsin / Tornado Warnings in 2009

Tornado Warning 35, NWS Twin Cities, MN

August 8, 2009Dunn County, Saint Croix County, Wisconsin

NWS Twin Cities, MN issued this tornado warning at Aug 8, 2009, 11:14 PM CDT for Dunn County, Saint Croix County, Wisconsin. It was in force for 46 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 8, 2009, 11:14 PM CDT (04:14 UTC)
Expired
Aug 9, 2009, 12:00 AM CDT
In force
46 min
Issued by
NWS Twin Cities, MN
Area
Storm-based polygon

Counties Dunn County, WI, Saint Croix County, WI

The radar

The Minneapolis radar (KMPX), 125 km from the middle of the area, began a volume at 04:16 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Aug 8, 3:46 PM CDTTornado WatchSPC8 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 4.2 hours before the alert went out and 127 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 2009-08-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3715 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 00:00Z on 2009-08-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 190 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
3715 J/kg
Mixed-layer CIN
-17 J/kg
Mixed-layer LCL
841 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
190 m²/s²
0-3 km storm-relative helicity
163 m²/s²
Significant tornado parameter
3.8
Supercell composite
16.8

Open this sounding in Storm Lab

The text

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

000 
WFUS53 KMPX 090414
TORMPX
WIC033-109-090500-
/O.NEW.KMPX.TO.W.0035.090809T0414Z-090809T0500Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1114 PM CDT SAT AUG 8 2009

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* TORNADO WARNING FOR...
  EAST CENTRAL ST. CROIX COUNTY IN WEST CENTRAL WISCONSIN...
  NORTHERN AND CENTRAL DUNN COUNTY IN WEST CENTRAL WISCONSIN...

* UNTIL MIDNIGHT CDT

* AT 1113 PM CDT...RADAR WAS TRACKING A SEVERE STORM WITH STRONG
  ROTATION. THE MOST DANGEROUS PART OF THE STORM WAS 3 MILES SOUTH OF
  EMERALD...AND MOVING EAST AT 25 MPH. THIS STORM PRODUCED DAMAGE
  TWO MILES NORTH OF BURKHARDT IN ST CROIX COUNTY.

* LOCATIONS IN THE WARNING INCLUDE...
  HERSEY...
  GLENWOOD CITY...
  WILSON...
  CONNORSVILLE...
  KNAPP...
  WHEELER...
  TAINTER LAKE...
  DOWNING...
  BOYCEVILLE...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

WHEN A TORNADO WARNING IS ISSUED BASED ON RADAR...IT MEANS THAT
STRONG ROTATION HAS BEEN DETECTED IN THE STORM. A TORNADO MAY ALREADY
BE ON THE GROUND...OR IS EXPECTED TO DEVELOP SHORTLY.

&&

LAT...LON 4518 9181 4492 9183 4496 9231 4512 9231
TIME...MOT...LOC 0413Z 276DEG 21KT 4504 9226

$$
2 follow-up statements
000 
WWUS53 KMPX 090435
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1135 PM CDT SAT AUG 8 2009

WIC033-109-090500-
/O.CON.KMPX.TO.W.0035.000000T0000Z-090809T0500Z/
ST. CROIX WI-DUNN WI-
1135 PM CDT SAT AUG 8 2009

...A TORNADO WARNING REMAINS IN EFFECT UNTIL MIDNIGHT CDT FOR CENTRAL
DUNN AND EAST CENTRAL ST. CROIX COUNTIES...

AT 1133 PM CDT...RADAR INDICATED A SEVERE THUNDERSTORM WITH STRONG
ROTATION.  THE MOST DANGEROUS PART OF THE STORM WAS LOCATED 3 MILES
NORTHWEST OF KNAPP...AND MOVING EAST AT 25 MPH.

LOCATIONS IN THE WARNING INCLUDE...
KNAPP...WHEELER...TAINTER LAKE AND BOYCEVILLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM HAS A HISTORY OR PRODUCING TORNADOES.

&&

LAT...LON 4496 9221 4513 9215 4518 9181 4492 9183
TIME...MOT...LOC 0434Z 276DEG 21KT 4499 9211

$$
000 
WWUS53 KMPX 090436 CCA
SVSMPX

SEVERE WEATHER STATEMENT...CORRECTION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1136 PM CDT SAT AUG 8 2009

WIC033-109-090500-
/O.CON.KMPX.TO.W.0035.000000T0000Z-090809T0500Z/
ST. CROIX WI-DUNN WI-
1136 PM CDT SAT AUG 8 2009

...A TORNADO WARNING REMAINS IN EFFECT UNTIL MIDNIGHT CDT FOR CENTRAL
DUNN AND EAST CENTRAL ST. CROIX COUNTIES...

AT 1133 PM CDT...RADAR INDICATED A SEVERE THUNDERSTORM WITH STRONG
ROTATION.  THE MOST DANGEROUS PART OF THE STORM WAS LOCATED 3 MILES
NORTHWEST OF KNAPP...AND MOVING EAST AT 25 MPH.

LOCATIONS IN THE WARNING INCLUDE...
KNAPP...WHEELER...TAINTER LAKE AND BOYCEVILLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM HAS A HISTORY OF PRODUCING TORNADOES.

&&

LAT...LON 4496 9221 4513 9215 4518 9181 4492 9183
TIME...MOT...LOC 0434Z 276DEG 21KT 4499 9211

$$

The office that day

Everything else NWS Twin Cities, MN issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 8, 9:43 PM CDTTornado WarningMPXPolk, Saint Croix32 min
Aug 8, 10:01 PM CDTTornado WarningMPXSaint Croix29 min
Aug 8, 10:14 PM CDTTornado WarningMPXPolk, Saint Croix31 min
Aug 8, 10:29 PM CDTTornado WarningMPXSaint Croix46 min
Aug 9, 12:00 AM CDTTornado WarningMPXDunn30 min
Aug 9, 12:36 AM CDTSpecial Weather StatementMPXChippewa, Eau Claire54 min
Aug 9, 1:27 AM CDTSpecial Weather StatementMPXChippewa33 min

Nearby

Tornado Warnings in Wisconsin, 2009Every tornado warning in 2009Tornadoes in 2009

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.