Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 66, NWS Twin Cities, MN

July 28, 20214 counties in Wisconsin

NWS Twin Cities, MN issued this severe thunderstorm warning at Jul 28, 2021, 10:09 PM CDT for 4 counties in Wisconsin. It was in force for 51 min. 3 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, 10:09 PM CDT (03:09 UTC)
Expired: Jul 28, 2021, 11:00 PM CDT
In force: 51 min
Issued by: NWS Twin Cities, MN
Area: Storm-based polygon
Hail: 1.0 in
Wind: 70.0 mph

Counties Dunn County, WI, Pepin County, WI, Pierce County, WI, Saint Croix County, WI

The radar

The Minneapolis radar (KMPX), 105 km from the middle of the area, began a volume at 03:13 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

Time	Report	Where	Remark
Jul 28, 10:15 PM CDT	TSTM WND DMG	2 Sw Spring Valley, WI	SURVEY DETERMINED A DOWNBURST HIT THE WEST SIDE OF SPRING VALLEY. NUMEROUS TREES WERE DOWN, WITH SOME LANDING ON HOUSES, SHEDS, AND VEHICLES. A SCHOOL GYMNASIUM ROOF WAS DAMAGED FROM THE WIND. ONE RESIDENT STATED THE WIND PERSISTED FOR MANY MINUTES.
Jul 28, 10:35 PM CDT	TSTM WND DMG	2 Wnw Durand, WI	NUMEROUS TREES DOWN, INCLUDING SOME ON HOUSES, VEHICLES, AND POWER LINES. A FEW TREES BLOCKED HIGHWAYS 10 AND 25.
Jul 28, 11:07 PM CDT	TSTM WND GST 60	6 Sw Durand, WI	MESONET STATION TT569 GANOE HILL.

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.

Issued	Product	Office	Lasted
Jul 28, 7:17 PM CDT	Severe Thunderstorm Watch PDS	SPC	7 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 3.2 hours before the alert went out and 107 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: 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.

429 
WUUS53 KMPX 290309
SVRMPX
WIC033-091-093-109-290400-
/O.NEW.KMPX.SV.W.0066.210729T0309Z-210729T0400Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Twin Cities/Chanhassen MN
1009 PM CDT Wed Jul 28 2021

The National Weather Service in the Twin Cities has issued a

* Severe Thunderstorm Warning for...
  Northeastern Pepin County in west central Wisconsin...
  Pierce County in west central Wisconsin...
  Southwestern Dunn County in west central Wisconsin...
  Southeastern St. Croix County in west central Wisconsin...

* Until 1100 PM CDT.

* At 1008 PM CDT, a severe thunderstorm was located near Woodville,
  or 12 miles east of River Falls, moving southeast at 40 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...
  Elmwood around 1025 PM CDT.

Other locations in the path of this severe thunderstorm include Eau
Galle, Plum City and Durand.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

To report severe weather, contact your nearest law enforcement
agency. They will send your report to the National Weather Service
office in the Twin Cities.

&&

LAT...LON 4459 9197 4460 9200 4458 9204 4458 9213
      4454 9214 4457 9255 4460 9256 4461 9261
      4464 9262 4476 9281 4486 9276 4492 9192
      4460 9171
TIME...MOT...LOC 0308Z 326DEG 35KT 4489 9236 

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

CTG

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 28, 7:19 PM CDT	Special Weather Statement	MPX	Rusk	26 min
Jul 28, 7:37 PM CDT	Severe Thunderstorm Warning	MPX	Rusk	23 min
Jul 28, 7:43 PM CDT	Severe Thunderstorm Warning	MPX	Barron, Polk, Rusk	32 min
Jul 28, 8:01 PM CDT	Severe Thunderstorm Warning	MPX	Barron, Chippewa, Rusk	44 min
Jul 28, 8:09 PM CDT	Tornado Warning	MPX	Polk	35 min
Jul 28, 8:46 PM CDT	Severe Thunderstorm Warning	MPX	Barron, Chippewa, Rusk	59 min
Jul 28, 8:55 PM CDT	Severe Thunderstorm Warning	MPX	Barron, Polk	50 min
Jul 28, 9:08 PM CDT	Tornado Warning	MPX	Chippewa	37 min
Jul 28, 9:25 PM CDT	Severe Thunderstorm Warning	MPX	Dunn, Saint Croix	65 min
Jul 28, 9:30 PM CDT	Severe Thunderstorm Warning	MPX	Chippewa, Eau Claire	60 min
Jul 28, 9:36 PM CDT	Tornado Warning	MPX	Saint Croix	24 min
Jul 28, 9:37 PM CDT	Severe Thunderstorm Warning	MPX	Saint Croix	38 min
Jul 28, 9:55 PM CDT	Tornado Warning	MPX	Saint Croix	35 min
Jul 28, 10:18 PM CDT	Severe Thunderstorm Warning	MPX	Dunn, Eau Claire, Pepin	42 min
Jul 28, 10:21 PM CDT	Severe Thunderstorm Warning	MPX	Saint Croix	24 min
Jul 28, 10:36 PM CDT	Severe Thunderstorm Warning	MPX	Pepin	39 min
Jul 28, 10:57 PM CDT	Severe Thunderstorm Warning	MPX	Dunn, Pepin, Pierce	48 min

Nearby

Severe Thunderstorm Warnings in Wisconsin, 2021 Every 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.