Alert archive / Wisconsin / Tornado Warnings in 2009

Tornado Warning 36, NWS Twin Cities, MN

August 9, 2009Dunn County, Wisconsin

NWS Twin Cities, MN issued this tornado warning at Aug 9, 2009, 12:00 AM CDT for Dunn County, Wisconsin. It was in force for 30 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 9, 2009, 12:00 AM CDT (05:00 UTC)
Expired
Aug 9, 2009, 12:30 AM CDT
In force
30 min
Issued by
NWS Twin Cities, MN
Area
Storm-based polygon

County Dunn County, WI

The radar

The La Crosse radar (KARX), 136 km from the middle of the area, began a volume at 05:04 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, 5.0 hours before the alert went out and 142 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 090500
TORMPX
WIC033-090545-
/O.NEW.KMPX.TO.W.0036.090809T0500Z-090809T0545Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1200 AM CDT SUN AUG 9 2009

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* TORNADO WARNING FOR...
  CENTRAL DUNN COUNTY IN WEST CENTRAL WISCONSIN...

* UNTIL 1245 AM CDT

* AT 1159 PM CDT...RADAR WAS TRACKING A SEVERE STORM WITH STRONG
  ROTATION. THE MOST DANGEROUS PART OF THE STORM WAS 5 MILES
  NORTHWEST OF MENOMONIE...OR ABOUT 5 MILES EAST OF KNAPP...AND
  MOVING EAST AT 20 MPH.

* LOCATIONS IN THE WARNING INCLUDE...
  MENOMONIE...
  TAINTER LAKE...
  COLFAX...
  ELK MOUND...

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.

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

&&

LAT...LON 4501 9166 4486 9166 4490 9204 4503 9201
TIME...MOT...LOC 0500Z 282DEG 17KT 4493 9198

$$
1 follow-up statement
000 
WWUS53 KMPX 090530
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1230 AM CDT SUN AUG 9 2009

WIC033-090539-
/O.CAN.KMPX.TO.W.0036.000000T0000Z-090809T0545Z/
DUNN WI-
1230 AM CDT SUN AUG 9 2009

...THE TORNADO WARNING FOR CENTRAL DUNN COUNTY IS CANCELLED...

RADAR INDICATED THAT THE SEVERE STORM HAD WEAKENED AND NO LONGER 
APPEARS TORNADIC. THEREFORE...THE TORNADO WARNING HAS BEEN CANCELLED.

LAT...LON 4501 9166 4486 9166 4490 9204 4503 9201
TIME...MOT...LOC 0529Z 282DEG 17KT 4490 9179

$$

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 8, 11:14 PM CDTTornado WarningMPXDunn, Saint Croix46 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.