Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 63, NWS Twin Cities, MN

July 28, 2021Dunn County, Saint Croix County, Wisconsin

NWS Twin Cities, MN issued this severe thunderstorm warning at Jul 28, 2021, 9:25 PM CDT for Dunn County, Saint Croix County, Wisconsin. It was in force for 65 min. 6 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
Jul 28, 2021, 9:25 PM CDT (02:25 UTC)
Expired
Jul 28, 2021, 10:30 PM CDT
In force
65 min
Issued by
NWS Twin Cities, MN
Area
Storm-based polygon
Hail
1.0 in
Wind
70.0 mph

Counties Dunn County, WI, Saint Croix County, WI

The radar

The Minneapolis radar (KMPX), 124 km from the middle of the area, began a volume at 02:28 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
Jul 28, 9:48 PM CDTTORNADO4 Se New Richmond, WITORNADO RATED EF1. PATH LENGTH 5.7 MILES. MAXIMUM WIDTH 100 YARDS. MAXIMUM WINDS ESTIMATED AT 95 MPH. THE TORNADO MOVED SOUTH-SOUTHEAST AND DAMAGED ABOUT ONE DOZEN HOMES INCLUDING ONE WHICH HAD ITS GARAGE BLOWN INTO AN ADJOINING FIELD. THE TORNADO ALSO TORE TH
Jul 28, 9:50 PM CDTTSTM WND DMG4 Ssw Deer Park, WISURVEY DETERMINED A DOWNBURST HIT THIS AREA. HUNDREDS OF TREES WERE DOWNED OR BROKEN ALONG A BROAD SWATH FROM 4 SSW DEER PARK TO 9 N BALDWIN. VIRTUALLY ALL WERE BLOWN DOWN FROM THE NORTH, NORTHEAST, OR EAST. MANY TREES WERE DOWN ACROSS ROADS AND DRIVEWAYS. THE
Jul 28, 9:50 PM CDTTSTM WND DMG5 Nnw Hammond, WIBARN AND GARAGE TAKEN DOWN, CORN FLATTENED AT COUNTY ROAD E AND 160TH ST. TIME ESTIMATED BY RADAR.
Jul 28, 9:55 PM CDTTSTM WND DMG3 W Deer Park, WIREPORT FROM MPING: 3-INCH TREE LIMBS BROKEN; POWER POLES BROKEN.
Jul 28, 9:55 PM CDTHAIL 1.5New Richmond, WIPICTURE VIA TWITTER, TIME ESTIMATED VIA RADAR.
Jul 28, 9:56 PM CDTHAIL 0.753 S New Richmond, WIREPORT FROM MPING: DIME (0.75 IN.).

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
Jul 28, 7:17 PM CDTSevere Thunderstorm Watch PDSSPC7 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 2.4 hours before the alert went out and 127 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 2021-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4815 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 00:00Z on 2021-07-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 374 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
4815 J/kg
Mixed-layer CIN
-38 J/kg
Mixed-layer LCL
1185 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
374 m²/s²
0-3 km storm-relative helicity
461 m²/s²
Significant tornado parameter
8.9
Supercell composite
48.1

Open this sounding in Storm Lab

The text

As transmitted.

660 
WUUS53 KMPX 290225
SVRMPX
WIC033-109-290330-
/O.NEW.KMPX.SV.W.0063.210729T0225Z-210729T0330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Twin Cities/Chanhassen MN
925 PM CDT Wed Jul 28 2021

The National Weather Service in the Twin Cities has issued a

* Severe Thunderstorm Warning for...
  Dunn County in west central Wisconsin...
  St. Croix County in west central Wisconsin...

* Until 1030 PM CDT.

* At 925 PM CDT, a severe thunderstorm was located near Glenwood
  City, or 19 miles northwest of Menomonie, moving southeast at 35
  mph.

  HAZARD...70 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect considerable 
           tree damage. Wind damage is also likely to mobile homes, 
           roofs, and outbuildings.

* This severe thunderstorm will be near...
  Boyceville around 940 PM CDT.
  Knapp around 945 PM CDT.

Other locations in the path of this severe thunderstorm include
Wheeler, Menomonie, Colfax and Elk Mound.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4485 9165 4487 9237 4521 9268 4521 9167
TIME...MOT...LOC 0225Z 313DEG 30KT 4513 9215 

HAIL...1.00IN
WIND...70MPH
 
$$

Dye
1 follow-up statement
217 
WWUS53 KMPX 290312
SVSMPX

Severe Weather Statement
National Weather Service Twin Cities/Chanhassen MN
1012 PM CDT Wed Jul 28 2021

WIC033-109-290330-
/O.CON.KMPX.SV.W.0063.000000T0000Z-210729T0330Z/
Dunn WI-St. Croix WI-
1012 PM CDT Wed Jul 28 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1030 PM CDT
FOR CENTRAL DUNN AND SOUTHEASTERN ST. CROIX COUNTIES...

At 1012 PM CDT, a severe thunderstorm was located near Elk Mound, or
8 miles east of Menomonie, moving southeast at 35 mph.

HAZARD...70 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect considerable 
         tree damage. Wind damage is also likely to mobile homes, 
         roofs, and outbuildings.

Locations impacted include...
  Elk Mound.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4485 9165 4487 9237 4511 9258 4511 9166
TIME...MOT...LOC 0312Z 313DEG 30KT 4486 9175 

HAIL...1.00IN
WIND...70MPH
 
$$

CTG

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 28, 7:19 PM CDTSpecial Weather StatementMPXRusk26 min
Jul 28, 7:37 PM CDTSevere Thunderstorm WarningMPXRusk23 min
Jul 28, 7:43 PM CDTSevere Thunderstorm WarningMPXBarron, Polk, Rusk32 min
Jul 28, 8:01 PM CDTSevere Thunderstorm WarningMPXBarron, Chippewa, Rusk44 min
Jul 28, 8:09 PM CDTTornado WarningMPXPolk35 min
Jul 28, 8:46 PM CDTSevere Thunderstorm WarningMPXBarron, Chippewa, Rusk59 min
Jul 28, 8:55 PM CDTSevere Thunderstorm WarningMPXBarron, Polk50 min
Jul 28, 9:08 PM CDTTornado WarningMPXChippewa37 min
Jul 28, 9:30 PM CDTSevere Thunderstorm WarningMPXChippewa, Eau Claire60 min
Jul 28, 9:36 PM CDTTornado WarningMPXSaint Croix24 min
Jul 28, 9:37 PM CDTSevere Thunderstorm WarningMPXSaint Croix38 min
Jul 28, 9:55 PM CDTTornado WarningMPXSaint Croix35 min
Jul 28, 10:09 PM CDTSevere Thunderstorm WarningMPXDunn, Pepin, Pierce, Saint Croix51 min
Jul 28, 10:18 PM CDTSevere Thunderstorm WarningMPXDunn, Eau Claire, Pepin42 min
Jul 28, 10:21 PM CDTSevere Thunderstorm WarningMPXSaint Croix24 min
Jul 28, 10:36 PM CDTSevere Thunderstorm WarningMPXPepin39 min
Jul 28, 10:57 PM CDTSevere Thunderstorm WarningMPXDunn, Pepin, Pierce48 min

Nearby

Severe Thunderstorm Warnings in Wisconsin, 2021Every severe thunderstorm warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.