Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 95, NWS Green Bay, WI

September 7, 2021Calumet County, Manitowoc County, Winnebago County, Wisconsin

NWS Green Bay, WI issued this severe thunderstorm warning at Sep 7, 2021, 9:30 AM CDT for Calumet County, Manitowoc County, Winnebago County, Wisconsin. It was in force for 60 min. 5 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
Sep 7, 2021, 9:30 AM CDT (14:30 UTC)
Expired
Sep 7, 2021, 10:30 AM CDT
In force
60 min
Issued by
NWS Green Bay, WI
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Calumet County, WI, Manitowoc County, WI, Winnebago County, WI

The radar

The Green Bay radar (KGRB), 60 km from the middle of the area, began a volume at 14:31 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
Sep 7, 9:39 AM CDTHAIL 12 S Oshkosh, WIAT EAA.
Sep 7, 9:49 AM CDTHAIL 11 N Stockbridge, WIREPORT FROM MPING.
Sep 7, 9:58 AM CDTHAIL 0.755 Se Wittman Field, WI
Sep 7, 10:04 AM CDTHAIL 1.251 Wsw Chilton, WIREPORTED AT CHILTON HIGH SCHOOL.
Sep 7, 10:15 AM CDTHAIL 1Chilton, WIREPORT FROM MPING.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 12:00Z, 2.5 hours before the alert went out and 59 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 2021-09-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 14 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, Green Bay/Straub, WI at 12:00Z on 2021-09-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -120 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
14 J/kg
Mixed-layer CIN
-216 J/kg
Mixed-layer LCL
1012 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
-120 m²/s²
0-3 km storm-relative helicity
35 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.1

Open this sounding in Storm Lab

The text

As transmitted.

559 
WUUS53 KGRB 071430
SVRGRB
WIC015-071-139-071530-
/O.NEW.KGRB.SV.W.0095.210907T1430Z-210907T1530Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Green Bay WI
930 AM CDT Tue Sep 7 2021

The National Weather Service in Green Bay has issued a

* Severe Thunderstorm Warning for...
  Calumet County in east central Wisconsin...
  Winnebago County in east central Wisconsin...
  Southwestern Manitowoc County in east central Wisconsin...

* Until 1030 AM CDT.

* At 929 AM CDT, a severe thunderstorm was located near Rush Lake, 
  or 9 miles west of Oshkosh, moving east at 60 mph. Spotters 
  reported one inch hail just north of Berlin.

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

  SOURCE...Trained weather spotters.

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

* This severe thunderstorm will be near...
  Oshkosh around 940 AM CDT.

Other locations in the path of this severe thunderstorm include
Central Lake Winnebago, Northern Lake Winnebago, Chilton, St.
Nazianz, Camp Rokilio Scout Camp and Valders.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 4414 8883 4414 8781 4389 8776 4389 8816
      4394 8816 4394 8840 4389 8841 4389 8886
TIME...MOT...LOC 1429Z 265DEG 52KT 4399 8875 

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

$$

Cooley
3 follow-up statements
116 
WWUS53 KGRB 071444
SVSGRB

Severe Weather Statement
National Weather Service Green Bay WI
944 AM CDT Tue Sep 7 2021

WIC015-071-139-071530-
/O.CON.KGRB.SV.W.0095.000000T0000Z-210907T1530Z/
Calumet WI-Winnebago WI-Manitowoc WI-
944 AM CDT Tue Sep 7 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1030 AM CDT
FOR CALUMET...SOUTHEASTERN WINNEBAGO AND SOUTHWESTERN MANITOWOC
COUNTIES...

At 943 AM CDT, a severe thunderstorm was located over Central Lake
Winnebago, or 8 miles east of Oshkosh, moving east at 60 mph.

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

SOURCE...Trained weather spotters.

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

This severe storm will be near...
  Chilton and St Anna around 955 AM CDT.
  Camp Rokilio Scout Camp around 1005 AM CDT.
  Valders and St. Nazianz around 1010 AM CDT.
  Cleveland around 1020 AM CDT.

Other locations impacted by this severe thunderstorm include Louis
Corners, St Nazianz, Pickett, Killsnake Wildlife Area, Jericho, Kiel,
Madsen, Millhome, Charlesburg and Brothertown.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Prepare immediately for large hail and deadly cloud to ground
lightning. Seek shelter inside a well-built structure. Stay away from
windows.

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

&&

LAT...LON 4389 8879 4414 8852 4414 8781 4389 8776
      4389 8816 4394 8816 4394 8840 4389 8841
TIME...MOT...LOC 1443Z 267DEG 51KT 4399 8839 

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

$$

KLJ
768 
WWUS53 KGRB 071508
SVSGRB

Severe Weather Statement
National Weather Service Green Bay WI
1008 AM CDT Tue Sep 7 2021

WIC015-071-139-071530-
/O.CON.KGRB.SV.W.0095.000000T0000Z-210907T1530Z/
Calumet WI-Winnebago WI-Manitowoc WI-
1008 AM CDT Tue Sep 7 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1030 AM CDT
FOR CALUMET...SOUTHEASTERN WINNEBAGO AND SOUTHWESTERN MANITOWOC
COUNTIES...

At 1007 AM CDT, a severe thunderstorm was located near St. Nazianz,
or 16 miles northwest of Howards Grove, moving east at 45 mph.

HAZARD...60 mph wind gusts and half dollar size hail.

SOURCE...Trained weather spotters. Half dollar sized hail was 
         reported at Chilton High School at 1004 AM CDT.

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

Locations impacted include...
Chilton, Cleveland, Valders, St. Nazianz, St Anna, Central Lake
Winnebago, Camp Rokilio Scout Camp, Harrison, Kiel and New Holstein.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Prepare immediately for large hail and deadly cloud to ground
lightning. Seek shelter inside a well-built structure. Stay away from
windows.

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

&&

LAT...LON 4389 8862 4414 8830 4414 8781 4389 8776
      4389 8816 4394 8816 4394 8840 4389 8841
TIME...MOT...LOC 1507Z 265DEG 40KT 4400 8803 

HAIL THREAT...OBSERVED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

KLJ
238 
WWUS53 KGRB 071523
SVSGRB

Severe Weather Statement
National Weather Service Green Bay WI
1023 AM CDT Tue Sep 7 2021

WIC015-071-139-071531-
/O.EXP.KGRB.SV.W.0095.000000T0000Z-210907T1530Z/
Calumet WI-Winnebago WI-Manitowoc WI-
1023 AM CDT Tue Sep 7 2021

...THE SEVERE THUNDERSTORM WARNING FOR CALUMET...SOUTHEASTERN
WINNEBAGO AND SOUTHWESTERN MANITOWOC COUNTIES WILL EXPIRE AT 1030 AM
CDT...
    
The severe thunderstorm which prompted the warning will be allowed 
to expire. However, a new Severe Thunderstorm Warning is now in 
effect for these storms. Large hail up to golf ball size remains 
possible. 

LAT...LON 4389 8862 4414 8830 4414 8781 4389 8776
      4389 8816 4394 8816 4394 8840 4389 8841
TIME...MOT...LOC 1521Z 268DEG 41KT 4395 8803 

$$

KLJ

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 7, 2:16 AM CDTSpecial Weather StatementGRBVilas89 min
Sep 7, 3:08 AM CDTSpecial Weather StatementGRBVilas97 min
Sep 7, 3:38 AM CDTSpecial Weather StatementGRBOneida, Vilas67 min
Sep 7, 4:22 AM CDTSpecial Weather StatementGRBFlorence, Forest, Langlade, Lincoln38 min
Sep 7, 5:23 AM CDTSpecial Weather StatementGRBMarinette, Menominee, Oconto52 min
Sep 7, 6:09 AM CDTSpecial Weather StatementGRBDoor, Oconto51 min
Sep 7, 6:17 AM CDTSpecial Marine WarningGRB88 min
Sep 7, 8:04 AM CDTSpecial Weather StatementGRBOutagamie, Waupaca41 min
Sep 7, 8:11 AM CDTSevere Thunderstorm WarningGRBOutagamie, Waupaca49 min
Sep 7, 8:16 AM CDTSpecial Marine WarningGRB59 min
Sep 7, 8:28 AM CDTSpecial Weather StatementGRBKewaunee62 min
Sep 7, 8:42 AM CDTSpecial Marine WarningGRB63 min
Sep 7, 8:42 AM CDTSevere Thunderstorm WarningGRBBrown, Outagamie48 min
Sep 7, 9:02 AM CDTSevere Thunderstorm WarningGRBWaushara, Winnebago43 min
Sep 7, 9:09 AM CDTSevere Thunderstorm WarningGRBBrown, Kewaunee, Manitowoc36 min
Sep 7, 9:16 AM CDTSevere Thunderstorm WarningGRBBrown, Calumet, Manitowoc, Outagamie, Winnebago44 min
Sep 7, 9:19 AM CDTSpecial Marine WarningGRB86 min
Sep 7, 9:48 AM CDTSpecial Weather StatementGRBKewaunee27 min
Sep 7, 10:18 AM CDTSevere Thunderstorm WarningGRBCalumet, Manitowoc42 min
Sep 7, 10:23 AM CDTSpecial Marine WarningGRB52 min
Sep 7, 11:14 AM CDTSpecial Marine WarningGRB26 min
Sep 7, 6:05 PM CDTSpecial Weather StatementGRBOneida, Vilas40 min
Sep 7, 6:44 PM CDTSpecial Weather StatementGRBForest, Oneida46 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.