Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 74, NWS Green Bay, WI

August 11, 20215 counties in Wisconsin

NWS Green Bay, WI issued this severe thunderstorm warning at Aug 11, 2021, 1:20 PM CDT for 5 counties in Wisconsin. It was in force for 40 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
Aug 11, 2021, 1:20 PM CDT (18:20 UTC)
Expired
Aug 11, 2021, 2:00 PM CDT
In force
40 min
Issued by
NWS Green Bay, WI
Area
Storm-based polygon
Tornado
Possible
Hail
1.0 in
Wind
60.0 mph

Counties Langlade County, WI, Lincoln County, WI, Marathon County, WI, Menominee County, WI, Shawano County, WI

The radar

The Green Bay radar (KGRB), 126 km from the middle of the area, began a volume at 18:21 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
Aug 11, 1:25 PM CDTTSTM WND GST 47Antigo, WIMEASURED AT ANTIGO RAWS - TIME ESTIMATED BY RADAR
Aug 11, 1:25 PM CDTTSTM WND GST 47Antigo, WIMEASURED AT ANTIGO RAWS - TIME ESTIMATED BY RADAR.
Aug 11, 1:40 PM CDTTSTM WND DMGAntigo, WIA TREE FELL ON POWERLINE.

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
Aug 11, 12:17 PM CDTTornado WatchSPC8 hr

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 12:00Z, 6.3 hours before the alert went out and 128 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, Green Bay/Straub, WI at 12:00Z on 2021-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1499 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, Green Bay/Straub, WI at 12:00Z on 2021-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 156 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
1499 J/kg
Mixed-layer CIN
-136 J/kg
Mixed-layer LCL
678 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
156 m²/s²
0-3 km storm-relative helicity
206 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.1

Open this sounding in Storm Lab

The text

As transmitted.

912 
WUUS53 KGRB 111820
SVRGRB
WIC067-069-073-078-115-111900-
/O.NEW.KGRB.SV.W.0074.210811T1820Z-210811T1900Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Green Bay WI
120 PM CDT Wed Aug 11 2021

The National Weather Service in Green Bay has issued a

* Severe Thunderstorm Warning for...
  Southeastern Lincoln County in north central Wisconsin...
  Northeastern Marathon County in central Wisconsin...
  Northwestern Menominee County in northeastern Wisconsin...
  Langlade County in north central Wisconsin...
  Western Shawano County in northeastern Wisconsin...

* Until 200 PM CDT.

* At 119 PM CDT, a severe thunderstorm was located near Antigo, 
  moving east at 50 mph. Other storms were located across Marathon 
  and Lincoln counties.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* Locations impacted include...
  White Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 800 PM CDT for central, north
central and northeastern Wisconsin.

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

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4513 9000 4541 8946 4540 8893 4538 8892
      4538 8868 4494 8871 4500 9001
TIME...MOT...LOC 1819Z 269DEG 43KT 4522 8917 

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Bersch
3 follow-up statements
394 
WWUS53 KGRB 111833
SVSGRB

Severe Weather Statement
National Weather Service Green Bay WI
133 PM CDT Wed Aug 11 2021

WIC067-069-073-078-115-111900-
/O.CON.KGRB.SV.W.0074.000000T0000Z-210811T1900Z/
Lincoln WI-Marathon WI-Menominee WI-Langlade WI-Shawano WI-
133 PM CDT Wed Aug 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 200 PM CDT
FOR SOUTHEASTERN LINCOLN...NORTHEASTERN MARATHON...NORTHWESTERN
MENOMINEE...LANGLADE AND WESTERN SHAWANO COUNTIES...

At 133 PM CDT, severe thunderstorms were located along a line
extending from 8 miles south of Ma Ka Ja Wan Scout Reservation to
near Antigo to 8 miles northeast of Weston, moving east at 45 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Wausau, Antigo, White Lake, Pearson, Neopit, Veterans Memorial County
Park, Ma Ka Ja Wan Scout Reservation, Langlade, Polar and Neva.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 800 PM CDT for central, north
central and northeastern Wisconsin.

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

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4511 8962 4540 8914 4540 8893 4538 8892
      4538 8868 4494 8871 4500 9001
TIME...MOT...LOC 1833Z 265DEG 38KT 4524 8896 4511 8917 4500 8947 

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Bersch
378 
WWUS53 KGRB 111842
SVSGRB

Severe Weather Statement
National Weather Service Green Bay WI
142 PM CDT Wed Aug 11 2021

WIC069-111852-
/O.CAN.KGRB.SV.W.0074.000000T0000Z-210811T1900Z/
Lincoln WI-
142 PM CDT Wed Aug 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN LINCOLN COUNTY IS
CANCELLED...

The storms which prompted the warning have moved out of the warned 
area. Therefore, the warning has been cancelled.

A Tornado Watch remains in effect until 800 PM CDT for central, north
central and northeastern Wisconsin.

LAT...LON 4515 8914 4534 8897 4540 8893 4538 8892
      4538 8868 4494 8871 4498 8955
TIME...MOT...LOC 1842Z 266DEG 33KT 4525 8885 4511 8907 4502 8932 

$$

WIC067-073-078-115-111900-
/O.CON.KGRB.SV.W.0074.000000T0000Z-210811T1900Z/
Marathon WI-Menominee WI-Langlade WI-Shawano WI-
142 PM CDT Wed Aug 11 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 200 PM CDT
FOR EAST CENTRAL MARATHON...NORTHWESTERN MENOMINEE...CENTRAL LANGLADE
AND WESTERN SHAWANO COUNTIES...

At 142 PM CDT, severe thunderstorms were located along a line
extending from 7 miles northwest of White Lake to near Antigo to 14
miles northeast of Weston, moving east at 40 mph.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Antigo, White Lake, Neopit, Langlade, Polar, Freeman, Mattoon, Aniwa,
Bryant and Lake Noseum.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 800 PM CDT for central, north
central and northeastern Wisconsin.

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

Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4515 8914 4534 8897 4540 8893 4538 8892
      4538 8868 4494 8871 4498 8955
TIME...MOT...LOC 1842Z 266DEG 33KT 4525 8885 4511 8907 4502 8932 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Bersch
631 
WWUS53 KGRB 111900 RRA
SVSGRB

Severe Weather Statement
National Weather Service Green Bay WI
200 PM CDT Wed Aug 11 2021

WIC067-073-078-115-111909-
/O.EXP.KGRB.SV.W.0074.000000T0000Z-210811T1900Z/
Marathon WI-Menominee WI-Langlade WI-Shawano WI-
200 PM CDT Wed Aug 11 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL MARATHON...
NORTHWESTERN MENOMINEE...CENTRAL LANGLADE AND WESTERN SHAWANO
COUNTIES WILL EXPIRE AT 200 PM CDT...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However gusty
winds and heavy rain are still possible with these thunderstorms.

A Tornado Watch remains in effect until 800 PM CDT for central, north
central and northeastern Wisconsin.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Green Bay.

Other severe thunderstorm warnings continue for parts of eastern 
Shawano and southeast M<enominee counties.

LAT...LON 4515 8914 4534 8897 4540 8893 4538 8892
      4538 8868 4494 8871 4498 8955
TIME...MOT...LOC 1859Z 269DEG 43KT 4525 8857 4511 8879 4502 8904 

$$

Kieckbusch

The office that day

Everything else NWS Green Bay, WI issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 10, 7:00 PM CDTSpecial Marine WarningGRB60 min
Aug 10, 7:06 PM CDTSpecial Marine WarningGRB54 min
Aug 10, 7:11 PM CDTFlash Flood WarningGRBBrown3 hr
Aug 10, 7:20 PM CDTSpecial Weather StatementGRBCalumet, Manitowoc55 min
Aug 10, 7:30 PM CDTSpecial Weather StatementGRBDoor, Marinette60 min
Aug 10, 7:49 PM CDTSpecial Marine WarningGRB86 min
Aug 10, 7:52 PM CDTSevere Thunderstorm WarningGRBCalumet, Kewaunee, Manitowoc38 min
Aug 10, 7:54 PM CDTTornado WarningGRBMarinette25 min
Aug 10, 10:05 PM CDTAreal Flood AdvisoryGRBBrown70 min
Aug 11, 3:11 AM CDTSmall Craft AdvisoryGRB19 hr
Aug 11, 11:25 AM CDTSpecial Weather StatementGRBOneida65 min
Aug 11, 11:54 AM CDTSpecial Weather StatementGRBLincoln, Marathon, Portage, Wood51 min
Aug 11, 12:18 PM CDTSevere Thunderstorm WarningGRBLincoln, Marathon42 min
Aug 11, 12:30 PM CDTSpecial Weather StatementGRBMarathon45 min
Aug 11, 12:38 PM CDTSevere Thunderstorm WarningGRBMarathon, Portage, Wood52 min
Aug 11, 12:42 PM CDTSpecial Weather StatementGRBFlorence, Forest33 min
Aug 11, 12:53 PM CDTSevere Thunderstorm WarningGRBFlorence, Forest, Marinette37 min
Aug 11, 12:57 PM CDTTornado WarningGRBLanglade, Lincoln, Marathon33 min
Aug 11, 1:04 PM CDTTornado WarningGRBMarathon41 min
Aug 11, 1:14 PM CDTSpecial Weather StatementGRBShawano46 min
Aug 11, 1:24 PM CDTSevere Thunderstorm WarningGRBMarathon, Menominee, Portage, Shawano, Waupaca51 min
Aug 11, 1:31 PM CDTSevere Thunderstorm WarningGRBOconto, Shawano, Waupaca44 min
Aug 11, 1:40 PM CDTTornado WarningGRBMarathon20 min
Aug 11, 1:54 PM CDTAreal Flood AdvisoryGRBMarathon, Menominee, Shawano3 hr
Aug 11, 1:54 PM CDTSevere Thunderstorm WarningGRBPortage, Wood51 min
Aug 11, 2:07 PM CDTTornado WarningGRBBrown, Oconto, Shawano23 min
Aug 11, 2:09 PM CDTTornado Warning Tornado observedGRBMarathon51 min
Aug 11, 2:16 PM CDTFlash Flood WarningGRBMarathon5 hr
Aug 11, 2:25 PM CDTSpecial Marine WarningGRB65 min
Aug 11, 2:27 PM CDTSevere Thunderstorm WarningGRBBrown, Oconto35 min
Aug 11, 2:37 PM CDTAreal Flood AdvisoryGRBMarinette, Oconto2 hr
Aug 11, 2:46 PM CDTSpecial Marine WarningGRB59 min
Aug 11, 2:47 PM CDTSevere Thunderstorm WarningGRBWaushara43 min
Aug 11, 2:47 PM CDTTornado WarningGRBMarathon43 min
Aug 11, 2:51 PM CDTSevere Thunderstorm WarningGRBBrown, Door, Kewaunee39 min
Aug 11, 2:55 PM CDTAreal Flood AdvisoryGRBDoor2 hr
Aug 11, 2:58 PM CDTSpecial Weather StatementGRBWaupaca47 min
Aug 11, 3:07 PM CDTFlash Flood WarningGRBMarathon4 hr
Aug 11, 3:08 PM CDTSevere Thunderstorm WarningGRBOutagamie, Shawano, Waupaca38 min
Aug 11, 3:11 PM CDTSpecial Marine WarningGRB64 min
Aug 11, 3:29 PM CDTSevere Thunderstorm Warning Considerable damage threatGRBWaushara18 min
Aug 11, 3:30 PM CDTSevere Thunderstorm WarningGRBBrown, Door, Kewaunee, Oconto, Outagamie, Shawano60 min
Aug 11, 3:33 PM CDTSpecial Marine WarningGRB57 min
Aug 11, 3:51 PM CDTSpecial Weather StatementGRBOutagamie, Winnebago39 min
Aug 11, 4:05 PM CDTSpecial Marine WarningGRB55 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.