Alert archive / Wisconsin / Tornado Warnings in 2009

Tornado Warning 49, NWS Twin Cities, MN

August 19, 2009Dunn County, Pierce County, Saint Croix County, Wisconsin

NWS Twin Cities, MN issued this tornado warning at Aug 19, 2009, 4:43 PM CDT for Dunn County, Pierce County, Saint Croix County, Wisconsin. It was in force for 47 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 19, 2009, 4:43 PM CDT (21:43 UTC)
Expired
Aug 19, 2009, 5:30 PM CDT
In force
47 min
Issued by
NWS Twin Cities, MN
Area
Storm-based polygon

Counties Dunn County, WI, Pierce County, WI, Saint Croix County, WI

The radar

The Minneapolis radar (KMPX), 110 km from the middle of the area, began a volume at 21:43 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 nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 9.7 hours before the alert went out and 112 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 2009-08-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 368 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 12:00Z on 2009-08-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 121 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
368 J/kg
Mixed-layer CIN
-49 J/kg
Mixed-layer LCL
615 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
121 m²/s²
0-3 km storm-relative helicity
68 m²/s²
Significant tornado parameter
0.2
Supercell composite
3.0

Open this sounding in Storm Lab

The text

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

000 
WFUS53 KMPX 192143
TORMPX
WIC033-093-109-192230-
/O.NEW.KMPX.TO.W.0049.090819T2143Z-090819T2230Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
443 PM CDT WED AUG 19 2009

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHEASTERN ST. CROIX COUNTY IN WEST CENTRAL WISCONSIN...
  WESTERN DUNN COUNTY IN WEST CENTRAL WISCONSIN...
  NORTHEASTERN PIERCE COUNTY IN WEST CENTRAL WISCONSIN...

* UNTIL 530 PM CDT

* AT 443 PM CDT...RADAR INDICATED A STORM CAPABLE OF PRODUCING A
  TORNADO. THE MOST DANGEROUS PART OF THE STORM WAS NEAR MARTEL...OR
  OVER MARTEL...AND MOVING NORTH AT 25 MPH.

* LOCATIONS IN THE WARNING INCLUDE...
  SPRING VALLEY...
  HAMMOND...
  BALDWIN...
  WOODVILLE...
  HERSEY...
  WILSON...
  KNAPP...

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.

IF YOU ARE CAUGHT OUTSIDE...SEEK SHELTER IN A NEARBY REINFORCED
BUILDING. AS A LAST RESORT...SEEK SHELTER IN A CULVERT...DITCH OR LOW
SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

&&

LAT...LON 4468 9210 4468 9213 4461 9215 4489 9248
      4503 9241 4502 9187
TIME...MOT...LOC 2143Z 201DEG 23KT 4484 9237

$$
2 follow-up statements
000 
WWUS53 KMPX 192153
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
453 PM CDT WED AUG 19 2009

WIC093-192203-
/O.CAN.KMPX.TO.W.0049.000000T0000Z-090819T2230Z/
PIERCE WI-
453 PM CDT WED AUG 19 2009

...THE TORNADO WARNING FOR NORTHEASTERN PIERCE COUNTY IS CANCELLED...

RADAR INDICATED THAT THE SEVERE STORM HAD MOVED OUT OF THE WARNED 
AREA. THEREFORE...THE TORNADO WARNING HAS BEEN CANCELLED.

A TORNADO WATCH REMAINS IN EFFECT UNTIL MIDNIGHT CDT THURSDAY MORNING
FOR NORTHWESTERN WISCONSIN.

LAT...LON 4468 9210 4468 9213 4486 9215 4486 9245
      4489 9248 4503 9241 4502 9187
TIME...MOT...LOC 2153Z 201DEG 23KT 4490 9234

$$

WIC033-109-192230-
/O.CON.KMPX.TO.W.0049.000000T0000Z-090819T2230Z/
ST. CROIX WI-DUNN WI-
453 PM CDT WED AUG 19 2009

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 530 PM CDT FOR
SOUTHWESTERN DUNN AND SOUTHEASTERN ST. CROIX COUNTIES...

AT 453 PM CDT...RADAR CONTINUED TO INDICATE A SEVERE THUNDERSTORM
CAPABLE OF PRODUCING A TORNADO.  THE MOST DANGEROUS PART OF THE STORM
WAS LOCATED 4 MILES SOUTHWEST OF WOODVILLE...AND MOVING NORTH AT 25
MPH.

LOCATIONS IN THE WARNING INCLUDE...
HAMMOND...BALDWIN...WOODVILLE...HERSEY...WILSON AND KNAPP.

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.

IF YOU ARE CAUGHT OUTSIDE...SEEK SHELTER IN A NEARBY REINFORCED
BUILDING. AS A LAST RESORT...SEEK SHELTER IN A CULVERT...DITCH OR LOW
SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

A TORNADO WATCH REMAINS IN EFFECT UNTIL MIDNIGHT CDT THURSDAY MORNING
FOR NORTHWESTERN WISCONSIN.

&&

LAT...LON 4468 9210 4468 9213 4486 9215 4486 9245
      4489 9248 4503 9241 4502 9187
TIME...MOT...LOC 2153Z 201DEG 23KT 4490 9234

$$
000 
WWUS53 KMPX 192218
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
518 PM CDT WED AUG 19 2009

WIC109-192228-
/O.CAN.KMPX.TO.W.0049.000000T0000Z-090819T2230Z/
ST. CROIX WI-
518 PM CDT WED AUG 19 2009

...THE TORNADO WARNING FOR SOUTHEASTERN ST. CROIX COUNTY IS
CANCELLED...

RADAR INDICATED THAT THE SEVERE STORM HAD MOVED OUT OF THE WARNED 
AREA. THEREFORE...THE TORNADO WARNING HAS BEEN CANCELLED.

A TORNADO WARNING REMAINS IN EFFECT UNTIL 6 PM FOR NORTHEAST 
ST CROIX COUNTY. 

A TORNADO WATCH REMAINS IN EFFECT UNTIL MIDNIGHT CDT THURSDAY MORNING
FOR NORTHWESTERN WISCONSIN.

LAT...LON 4489 9207 4495 9213 4502 9213 4502 9187
      4478 9203
TIME...MOT...LOC 2218Z 200DEG 25KT 4493 9201

$$

WIC033-192230-
/O.CON.KMPX.TO.W.0049.000000T0000Z-090819T2230Z/
DUNN WI-
518 PM CDT WED AUG 19 2009

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 530 PM CDT FOR WEST
CENTRAL DUNN COUNTY...

AT 517 PM CDT...RADAR CONTINUED TO INDICATE A SEVERE THUNDERSTORM
CAPABLE OF PRODUCING A TORNADO.  THE MOST DANGEROUS PART OF THE STORM
WAS LOCATED 4 MILES SOUTHEAST OF KNAPP...AND MOVING NORTH AT 30 MPH.

LOCATIONS IN THE WARNING INCLUDE...
KNAPP.

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.

IF YOU ARE CAUGHT OUTSIDE...SEEK SHELTER IN A NEARBY REINFORCED
BUILDING. AS A LAST RESORT...SEEK SHELTER IN A CULVERT...DITCH OR LOW
SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

A TORNADO WATCH REMAINS IN EFFECT UNTIL MIDNIGHT CDT THURSDAY MORNING
FOR NORTHWESTERN WISCONSIN.

&&

LAT...LON 4489 9207 4495 9213 4502 9213 4502 9187
      4478 9203
TIME...MOT...LOC 2218Z 200DEG 25KT 4493 9201

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 19, 2:43 PM CDTTornado WarningMPXPierce32 min
Aug 19, 2:53 PM CDTTornado WarningMPXSaint Croix22 min
Aug 19, 2:57 PM CDTTornado WarningMPXPierce, Saint Croix48 min
Aug 19, 3:16 PM CDTTornado WarningMPXPolk, Saint Croix29 min
Aug 19, 4:04 PM CDTTornado WarningMPXDunn, Saint Croix26 min
Aug 19, 4:06 PM CDTTornado WarningMPXPierce, Saint Croix39 min
Aug 19, 4:14 PM CDTTornado WarningMPXBarron, Polk46 min
Aug 19, 4:21 PM CDTTornado WarningMPXPolk39 min
Aug 19, 4:33 PM CDTTornado WarningMPXSaint Croix27 min
Aug 19, 5:13 PM CDTTornado WarningMPXBarron, Dunn, Polk, Saint Croix47 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.