Alert archive / Wisconsin / Tornado Warnings in 2021

Tornado Warning 25, NWS Twin Cities, MN

September 20, 2021Dunn County, Pepin County, Pierce County, Wisconsin

NWS Twin Cities, MN issued this tornado warning at Sep 20, 2021, 4:43 PM CDT for Dunn County, Pepin County, Pierce County, Wisconsin. It was in force for 14 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: Sep 20, 2021, 4:43 PM CDT (21:43 UTC)
Expired: Sep 20, 2021, 4:57 PM CDT
In force: 14 min
Issued by: NWS Twin Cities, MN
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

Counties Dunn County, WI, Pepin County, WI, Pierce County, WI

The radar

The Minneapolis radar (KMPX), 115 km from the middle of the area, began a volume at 21:47 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.

Issued	Product	Office	Lasted
Sep 20, 2:07 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 9.7 hours before the alert went out and 118 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 148 J/kg
Mixed-layer CIN: -141 J/kg
Mixed-layer LCL: 1002 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 210 m²/s²
0-3 km storm-relative helicity: 162 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.4

Open this sounding in Storm Lab

The text

As transmitted.

536 
WFUS53 KMPX 202143
TORMPX
WIC033-091-093-202215-
/O.NEW.KMPX.TO.W.0025.210920T2143Z-210920T2215Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Twin Cities/Chanhassen MN
443 PM CDT Mon Sep 20 2021

The National Weather Service in the Twin Cities has issued a

* Tornado Warning for...
  North central Pepin County in west central Wisconsin...
  Southeastern Pierce County in west central Wisconsin...
  Southwestern Dunn County in west central Wisconsin...

* Until 515 PM CDT.
    
* At 443 PM CDT, a severe thunderstorm capable of producing a tornado
  was located over Plum City, or 17 miles east of Red Wing, moving
  northeast at 35 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur. Tree 
           damage is likely.

* This dangerous storm will be near...
  Eau Galle around 500 PM CDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4459 9223 4464 9229 4486 9201 4471 9188
TIME...MOT...LOC 2143Z 235DEG 30KT 4464 9221 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...<.75 IN

$$

Borghoff

1 follow-up statement

327 
WWUS53 KMPX 202157
SVSMPX

Severe Weather Statement
National Weather Service Twin Cities/Chanhassen MN
457 PM CDT Mon Sep 20 2021

WIC033-091-093-202207-
/O.CAN.KMPX.TO.W.0025.000000T0000Z-210920T2215Z/
Pepin WI-Pierce WI-Dunn WI-
457 PM CDT Mon Sep 20 2021

...THE TORNADO WARNING FOR NORTH CENTRAL PEPIN...SOUTHEASTERN PIERCE
AND SOUTHWESTERN DUNN COUNTIES IS CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore, the warning has been cancelled.

A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
west central Wisconsin.

LAT...LON 4459 9223 4464 9229 4486 9201 4471 9188
TIME...MOT...LOC 2156Z 235DEG 30KT 4474 9202 

$$

Borghoff

Nearby

Tornado Warnings in Wisconsin, 2021 Every tornado warning in 2021 Tornadoes in 2021

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.