Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 94, NWS Green Bay, WI

September 7, 20215 counties in Wisconsin

NWS Green Bay, WI issued this severe thunderstorm warning at Sep 7, 2021, 9:16 AM CDT for 5 counties in Wisconsin. It was in force for 44 min. 4 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, 9:16 AM CDT (14:16 UTC)
Expired
Sep 7, 2021, 10:00 AM CDT
In force
44 min
Issued by
NWS Green Bay, WI
Area
Storm-based polygon
Hail
1.5 in
Wind
60.0 mph

Counties Brown County, WI, Calumet County, WI, Manitowoc County, WI, Outagamie County, WI, Winnebago County, WI

The radar

The Green Bay radar (KGRB), 34 km from the middle of the area, began a volume at 14:15 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, 9:18 AM CDTHAIL 1Kaukauna, WI
Sep 7, 9:18 AM CDTHAIL 1.5Kaukauna, WINEAR HWY 55 / CE.
Sep 7, 9:32 AM CDTHAIL 1.25Maribel, WIHIGHWAY NN AND HIGHWAY Z.
Sep 7, 9:37 AM CDTHAIL 1.252 Nne Wayside, 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, 2.3 hours before the alert went out and 31 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°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.

987 
WUUS53 KGRB 071416
SVRGRB
WIC009-015-071-087-139-071500-
/O.NEW.KGRB.SV.W.0094.210907T1416Z-210907T1500Z/

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

The National Weather Service in Green Bay has issued a

* Severe Thunderstorm Warning for...
  South central Brown County in northeastern Wisconsin...
  Northern Calumet County in east central Wisconsin...
  Northeastern Winnebago County in east central Wisconsin...
  Southeastern Outagamie County in northeastern Wisconsin...
  Northern Manitowoc County in east central Wisconsin...

* Until 1000 AM CDT.

* At 914 AM CDT, a severe thunderstorm was located over Darboy, or 
  near Appleton, moving east at 55 mph. Ping pong ball size hail was 
  reported in Appleton 912 am.

  HAZARD...Ping pong ball size hail and 60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...People and animals outdoors will be injured. Expect hail 
           damage to roofs, siding, windows, and vehicles. Expect 
           wind damage to roofs, siding, and trees.

* This severe thunderstorm will be near...
  Brillion around 930 AM CDT.

Other locations in the path of this severe thunderstorm include Two
Creeks.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This storm is producing large hail. SEEK SHELTER NOW inside a sturdy
structure and 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 4414 8854 4426 8857 4433 8775 4433 8754
      4435 8753 4435 8748 4417 8747 4413 8752
TIME...MOT...LOC 1414Z 269DEG 47KT 4425 8834 

HAIL THREAT...OBSERVED
MAX HAIL SIZE...1.50 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Cooley
3 follow-up statements
707 
WWUS53 KGRB 071429
SVSGRB

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

WIC009-015-071-087-139-071500-
/O.CON.KGRB.SV.W.0094.000000T0000Z-210907T1500Z/
Brown WI-Calumet WI-Winnebago WI-Outagamie WI-Manitowoc WI-
929 AM CDT Tue Sep 7 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 AM CDT
FOR SOUTH CENTRAL BROWN...NORTHERN CALUMET...NORTHEASTERN
WINNEBAGO...SOUTHEASTERN OUTAGAMIE AND NORTHERN MANITOWOC COUNTIES...

At 927 AM CDT, a severe thunderstorm was located near Brillion, or 
17 miles east of Appleton, moving east at 55 mph. Another storm was 
west of Menasha moving east at 55 mph capable of producing 1 inch 
hail.

HAZARD...Ping pong ball size hail and 60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

Locations impacted include...
  Two Creeks.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This storm is producing large hail. SEEK SHELTER NOW inside a sturdy
structure and 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 4414 8854 4426 8857 4433 8780 4433 8754
      4435 8753 4435 8748 4417 8747 4413 8752
TIME...MOT...LOC 1427Z 267DEG 49KT 4426 8804 

HAIL THREAT...OBSERVED
MAX HAIL SIZE...1.50 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

KLJ
820 
WWUS53 KGRB 071442
SVSGRB

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

WIC139-071450-
/O.CAN.KGRB.SV.W.0094.000000T0000Z-210907T1500Z/
Winnebago WI-
942 AM CDT Tue Sep 7 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN WINNEBAGO COUNTY
IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 4414 8841 4421 8841 4428 8836 4433 8781
      4433 8754 4435 8753 4435 8748 4417 8747
      4413 8752
TIME...MOT...LOC 1440Z 265DEG 47KT 4427 8781 

$$

WIC009-015-071-087-071500-
/O.CON.KGRB.SV.W.0094.000000T0000Z-210907T1500Z/
Brown WI-Calumet WI-Outagamie WI-Manitowoc WI-
942 AM CDT Tue Sep 7 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 AM CDT
FOR SOUTHEASTERN BROWN...NORTHERN CALUMET...SOUTHEASTERN OUTAGAMIE
AND NORTHERN MANITOWOC COUNTIES...

At 940 AM CDT, a severe thunderstorm was located near Denmark, or 13 
miles northwest of Manitowoc, moving east at 55 mph. Another storm 
was located near Kaukauna and moving east at 55 mph. 

HAZARD...Ping pong ball size hail and 60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees.

Locations impacted include...
Appleton, Manitowoc, Menasha, Kaukauna, Little Chute, Kimberly,
Brillion, Two Creeks, Northern Lake Winnebago and Darboy.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

This storm is producing large hail. SEEK SHELTER NOW inside a sturdy
structure and 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 4414 8841 4421 8841 4428 8836 4433 8781
      4433 8754 4435 8753 4435 8748 4417 8747
      4413 8752
TIME...MOT...LOC 1440Z 265DEG 47KT 4427 8781 

HAIL THREAT...OBSERVED
MAX HAIL SIZE...1.50 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

KLJ
855 
WWUS53 KGRB 071449
SVSGRB

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

WIC087-071459-
/O.CAN.KGRB.SV.W.0094.000000T0000Z-210907T1500Z/
Outagamie WI-
949 AM CDT Tue Sep 7 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN OUTAGAMIE COUNTY
IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 4414 8813 4431 8810 4433 8782 4433 8754
      4435 8753 4435 8748 4417 8747 4413 8752
TIME...MOT...LOC 1449Z 266DEG 46KT 4429 8766 

$$

WIC009-015-071-071500-
/O.CON.KGRB.SV.W.0094.000000T0000Z-210907T1500Z/
Brown WI-Calumet WI-Manitowoc WI-
949 AM CDT Tue Sep 7 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 AM CDT
FOR SOUTHEASTERN BROWN...NORTHEASTERN CALUMET AND NORTHERN MANITOWOC
COUNTIES...

At 949 AM CDT, a severe thunderstorm was located near Two Creeks, or
13 miles north of Manitowoc, moving east at 50 mph.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Manitowoc, Brillion, Two Creeks, Two Rivers, Morrison, Cato,
Mishicot, Larrabee, Cooperstown and Reedsville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

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

&&

LAT...LON 4414 8813 4431 8810 4433 8782 4433 8754
      4435 8753 4435 8748 4417 8747 4413 8752
TIME...MOT...LOC 1449Z 266DEG 46KT 4429 8766 

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

$$

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, 9:19 AM CDTSpecial Marine WarningGRB86 min
Sep 7, 9:30 AM CDTSevere Thunderstorm WarningGRBCalumet, Manitowoc, Winnebago60 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.