Alert archive / Wisconsin / Tornado Warnings in 2009

Tornado Warning 34, NWS Twin Cities, MN

August 8, 2009Saint Croix County, Wisconsin

NWS Twin Cities, MN issued this tornado warning at Aug 8, 2009, 10:29 PM CDT for Saint Croix County, Wisconsin. It was in force for 46 min. 4 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Aug 8, 2009, 10:29 PM CDT (03:29 UTC)
Expired
Aug 8, 2009, 11:15 PM CDT
In force
46 min
Issued by
NWS Twin Cities, MN
Area
Storm-based polygon

County Saint Croix County, WI

The radar

The Minneapolis radar (KMPX), 90 km from the middle of the area, began a volume at 03:30 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 was reported inside it

TimeReportWhereRemark
Aug 8, 10:40 PM CDTTSTM WND DMG2 N Burkhardt, WINUMEROUS POWER LINES AND TREES TOPPLED IN ST JOSEPH TOWNSHIP NEAR OAKWOOD LANE. HOME OWNER AT 1223 OAKWOOD LANE REPORTED GARAGE RIPPED APART AND BOAT SUCKED AWAY.
Aug 8, 10:45 PM CDTTSTM WND DMG2 Nnw Hammond, WIGARAGE DOORS BLOWN IN. PORTION OF A ROOF BLOWN OFF HOUSE. CORN BLOWN DOWN. DAMAGE IN THE AREA OF 167TH STREET. TIME ESTIMATED FROM RADAR.
Aug 8, 10:51 PM CDTTORNADO4 Nnw Hammond, WIDAMAGE SURVEY DETERMINED EF-0 TORNADO FOR ABOUT 1/2 MILE. SEVERAL GARAGE DOORS WERE BLOWN IN. PORTION OF A ROOF BLOWN OFF HOUSE. NUMEROUS SOFFETS BLOWN OFF. CORN BLOWN DOWN. DAMAGE IN THE AREA OF 167TH STREET. TIME ESTIMATED FROM RADAR.
Aug 8, 11:11 PM CDTTSTM WND DMGBoardman, WIDAMAGE SURVEY PLANNED AROUND BOARDMAN AND BURKHARDT.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

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, 3.5 hours before the alert went out and 93 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 090329
TORMPX
WIC109-090415-
/O.NEW.KMPX.TO.W.0034.090809T0329Z-090809T0415Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1029 PM CDT SAT AUG 8 2009

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* TORNADO WARNING FOR...
  WEST CENTRAL TO EAST CENTRAL ST. CROIX COUNTY IN WEST CENTRAL
  WISCONSIN...

* UNTIL 1115 PM CDT

* AT 1026 PM CDT...RADAR WAS TRACKING A SEVERE STORM WITH STRONG
  ROTATION. THE MOST DANGEROUS PART OF THE STORM WAS NEAR
  BURKHARDT...AND MOVING EAST AT 20 MPH.

* LOCATIONS IN THE WARNING INCLUDE...
  HOULTON...
  ROBERTS...
  HAMMOND...
  CYLON...
  BOARDMAN...
  AREAS SOUTH OF NEW RICHMOND...

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 4513 9230 4496 9229 4498 9268 4508 9270
TIME...MOT...LOC 0328Z 272DEG 17KT 4504 9263

$$
2 follow-up statements
000 
WWUS53 KMPX 090340
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1040 PM CDT SAT AUG 8 2009

WIC109-090415-
/O.CON.KMPX.TO.W.0034.000000T0000Z-090809T0415Z/
ST. CROIX WI-
1040 PM CDT SAT AUG 8 2009

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1115 PM CDT FOR CENTRAL 
AND EAST CENTRAL ST. CROIX COUNTY...

AT 1037 PM CDT...RADAR INDICATED A SEVERE THUNDERSTORM WITH STRONG
ROTATION.  THE MOST DANGEROUS PART OF THE STORM WAS LOCATED NEAR 
HOULTON...AND MOVING EAST AT 20 MPH.  THE TORNADO IS LIKELY WRAPPED 
IN RAIN.

LOCATIONS IN THE WARNING INCLUDE...
HOULTON...ROBERTS...HAMMOND AND CYLON.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM HAS A HISTORY OR PRODUCING TORNADOES AND LARGE DAMAGING
HAIL.

&&

LAT...LON 4498 9261 4509 9262 4513 9230 4496 9229
TIME...MOT...LOC 0338Z 272DEG 17KT 4504 9257

$$
000 
WWUS53 KMPX 090351
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1051 PM CDT SAT AUG 8 2009

WIC109-090415-
/O.CON.KMPX.TO.W.0034.000000T0000Z-090809T0415Z/
ST. CROIX WI-
1051 PM CDT SAT AUG 8 2009

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1115 PM CDT FOR CENTRAL 
AND EAST CENTRAL ST. CROIX COUNTY...

AT 1049 PM CDT...RADAR INDICATED A SEVERE THUNDERSTORM WITH STRONG
ROTATION.  THE MOST DANGEROUS PART OF THE STORM WAS LOCATED 4 MILES
NORTH OF HAMMOND...AND MOVING EAST AT 25 MPH.

LOCATIONS IN THE WARNING INCLUDE...
HAMMOND AND CYLON.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM HAS A HISTORY OR PRODUCING TORNADOES AND LARGE DAMAGING
HAIL.

&&

LAT...LON 4498 9252 4510 9249 4513 9230 4496 9229
TIME...MOT...LOC 0350Z 276DEG 21KT 4503 9246

$$

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, 11:14 PM CDTTornado WarningMPXDunn, Saint 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.