Alert archive / Wisconsin / Tornado Warnings in 2009

Tornado Warning 39, NWS Twin Cities, MN

August 19, 2009Pierce County, Wisconsin

NWS Twin Cities, MN issued this tornado warning at Aug 19, 2009, 2:43 PM CDT for Pierce County, Wisconsin. It was in force for 32 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, 2:43 PM CDT (19:43 UTC)
Expired
Aug 19, 2009, 3:15 PM CDT
In force
32 min
Issued by
NWS Twin Cities, MN
Area
Storm-based polygon

County Pierce County, WI

The radar

The Minneapolis radar (KMPX), 72 km from the middle of the area, began a volume at 19:44 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, 7.7 hours before the alert went out and 75 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 191943
TORMPX
WIC093-192015-
/O.NEW.KMPX.TO.W.0039.090819T1943Z-090819T2015Z/

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

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHWESTERN PIERCE COUNTY IN WEST CENTRAL WISCONSIN...

* UNTIL 315 PM CDT

* AT 243 PM CDT...RADAR INDICATED A STORM CAPABLE OF PRODUCING A
  TORNADO. THE MOST DANGEROUS PART OF THE STORM WAS 4 MILES NORTHWEST
  OF DIAMOND BLUFF...AND MOVING NORTH AT 25 MPH.

* LOCATIONS IN THE WARNING INCLUDE...
  RIVER FALLS...

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 4471 9274 4486 9276 4486 9253 4486 9252
      4464 9263
TIME...MOT...LOC 1943Z 188DEG 23KT 4469 9269

$$

The office that day

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

IssuedProductOfficeCountiesLasted
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, 4:43 PM CDTTornado WarningMPXDunn, Pierce, Saint Croix47 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.