Alert archive / Wisconsin / Tornado Warnings in 2021

Tornado Warning 8, NWS Green Bay, WI

August 11, 2021Marathon County, Wisconsin

NWS Green Bay, WI issued this tornado warning at Aug 11, 2021, 1:04 PM CDT for Marathon County, Wisconsin. It was in force for 41 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Aug 11, 2021, 1:04 PM CDT (18:04 UTC)
Expired: Aug 11, 2021, 1:45 PM CDT
In force: 41 min
Issued by: NWS Green Bay, WI
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.0 in

County Marathon County, WI

The radar

The La Crosse radar (KARX), 153 km from the middle of the area, began a volume at 18:04 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Aug 11, 12:17 PM CDT	Tornado Watch	SPC	8 hr

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 12:00Z, 6.1 hours before the alert went out and 167 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: 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.

710 
WFUS53 KGRB 111804
TORGRB
WIC073-111845-
/O.NEW.KGRB.TO.W.0008.210811T1804Z-210811T1845Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Green Bay WI
104 PM CDT Wed Aug 11 2021

The National Weather Service in Green Bay has issued a

* Tornado Warning for...
  Northwestern Marathon County in central Wisconsin...

* Until 145 PM CDT.
    
* At 103 PM CDT, a severe thunderstorm capable of producing a tornado
  was located near Colby, or 17 miles south of Medford, moving east
  at 50 mph.

  HAZARD...Tornado and quarter size hail.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* This tornadic thunderstorm will remain over mainly rural areas of
  northwestern Marathon County, including the following locations...
  Edgar, Cherokee, Little Chicago, March Rapids, Hamburg,
  Poniatowski, Athens, Rib Falls, Fenwood and Milan.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

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

&&

LAT...LON 4500 9031 4511 8985 4485 8973 4481 9032
TIME...MOT...LOC 1803Z 255DEG 42KT 4489 9038 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.00 IN

$$

Cooley

3 follow-up statements

241 
WWUS53 KGRB 111814
SVSGRB

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

WIC073-111845-
/O.CON.KGRB.TO.W.0008.000000T0000Z-210811T1845Z/
Marathon WI-
114 PM CDT Wed Aug 11 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 145 PM CDT FOR
NORTHWESTERN MARATHON COUNTY...
    
At 114 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Colby, or 16 miles south of Medford, moving east at
50 mph.

HAZARD...Tornado and quarter size hail.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

Locations impacted include...
Abbotsford, Colby, Marathon City, Edgar, Athens, Rib Falls, Unity,
Fenwood, Cherokee and Little Chicago.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

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

&&

LAT...LON 4496 9031 4508 8985 4485 8973 4481 9032
TIME...MOT...LOC 1814Z 257DEG 37KT 4491 9023 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.00 IN

$$

Cooley

577 
WWUS53 KGRB 111825
SVSGRB

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

WIC073-111845-
/O.CON.KGRB.TO.W.0008.000000T0000Z-210811T1845Z/
Marathon WI-
125 PM CDT Wed Aug 11 2021

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 145 PM CDT FOR
NORTHWESTERN MARATHON COUNTY...
    
At 125 PM CDT, a severe thunderstorm capable of producing a tornado
was located 8 miles east of Colby, or 20 miles southeast of Medford,
moving east at 45 mph.

HAZARD...Tornado and quarter size hail.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

Locations impacted include...
Marathon City, Edgar, Rib Falls, Fenwood, Cherokee, Little Chicago,
March Rapids and Poniatowski.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

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

&&

LAT...LON 4493 9026 4504 8984 4485 8973 4481 9027
TIME...MOT...LOC 1825Z 262DEG 39KT 4488 9014 

TORNADO...RADAR INDICATED
MAX HAIL SIZE...1.00 IN

$$

Cooley

148 
WWUS53 KGRB 111844
SVSGRB

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

WIC073-111852-
/O.EXP.KGRB.TO.W.0008.000000T0000Z-210811T1845Z/
Marathon WI-
144 PM CDT Wed Aug 11 2021

...THE TORNADO WARNING FOR NORTHWESTERN MARATHON COUNTY WILL EXPIRE
AT 145 PM CDT...
    
The tornadic thunderstorm which prompted the warning has move. moved 
out of the warned area. Therefore, the warning will be allowed to 
expire.

Remember, a Tornado Warning still remains in effect for portions of 
central Marathon County. 

A Tornado Watch remains in effect until 800 PM CDT for central
Wisconsin.



LAT...LON 4493 9026 4504 8984 4485 8973 4481 9027
TIME...MOT...LOC 1842Z 255DEG 42KT 4493 8988 

$$

Cooley

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 10, 7:00 PM CDT	Special Marine Warning	GRB		60 min
Aug 10, 7:06 PM CDT	Special Marine Warning	GRB		54 min
Aug 10, 7:11 PM CDT	Flash Flood Warning	GRB	Brown	3 hr
Aug 10, 7:20 PM CDT	Special Weather Statement	GRB	Calumet, Manitowoc	55 min
Aug 10, 7:30 PM CDT	Special Weather Statement	GRB	Door, Marinette	60 min
Aug 10, 7:49 PM CDT	Special Marine Warning	GRB		86 min
Aug 10, 7:52 PM CDT	Severe Thunderstorm Warning	GRB	Calumet, Kewaunee, Manitowoc	38 min
Aug 10, 7:54 PM CDT	Tornado Warning	GRB	Marinette	25 min
Aug 10, 10:05 PM CDT	Areal Flood Advisory	GRB	Brown	70 min
Aug 11, 3:11 AM CDT	Small Craft Advisory	GRB		19 hr
Aug 11, 11:25 AM CDT	Special Weather Statement	GRB	Oneida	65 min
Aug 11, 11:54 AM CDT	Special Weather Statement	GRB	Lincoln, Marathon, Portage, Wood	51 min
Aug 11, 12:18 PM CDT	Severe Thunderstorm Warning	GRB	Lincoln, Marathon	42 min
Aug 11, 12:30 PM CDT	Special Weather Statement	GRB	Marathon	45 min
Aug 11, 12:38 PM CDT	Severe Thunderstorm Warning	GRB	Marathon, Portage, Wood	52 min
Aug 11, 12:42 PM CDT	Special Weather Statement	GRB	Florence, Forest	33 min
Aug 11, 12:53 PM CDT	Severe Thunderstorm Warning	GRB	Florence, Forest, Marinette	37 min
Aug 11, 12:57 PM CDT	Tornado Warning	GRB	Langlade, Lincoln, Marathon	33 min
Aug 11, 1:14 PM CDT	Special Weather Statement	GRB	Shawano	46 min
Aug 11, 1:20 PM CDT	Severe Thunderstorm Warning	GRB	Langlade, Lincoln, Marathon, Menominee, Shawano	40 min
Aug 11, 1:24 PM CDT	Severe Thunderstorm Warning	GRB	Marathon, Menominee, Portage, Shawano, Waupaca	51 min
Aug 11, 1:31 PM CDT	Severe Thunderstorm Warning	GRB	Oconto, Shawano, Waupaca	44 min
Aug 11, 1:40 PM CDT	Tornado Warning	GRB	Marathon	20 min
Aug 11, 1:54 PM CDT	Areal Flood Advisory	GRB	Marathon, Menominee, Shawano	3 hr
Aug 11, 1:54 PM CDT	Severe Thunderstorm Warning	GRB	Portage, Wood	51 min
Aug 11, 2:07 PM CDT	Tornado Warning	GRB	Brown, Oconto, Shawano	23 min
Aug 11, 2:09 PM CDT	Tornado Warning Tornado observed	GRB	Marathon	51 min
Aug 11, 2:16 PM CDT	Flash Flood Warning	GRB	Marathon	5 hr
Aug 11, 2:25 PM CDT	Special Marine Warning	GRB		65 min
Aug 11, 2:27 PM CDT	Severe Thunderstorm Warning	GRB	Brown, Oconto	35 min
Aug 11, 2:37 PM CDT	Areal Flood Advisory	GRB	Marinette, Oconto	2 hr
Aug 11, 2:46 PM CDT	Special Marine Warning	GRB		59 min
Aug 11, 2:47 PM CDT	Severe Thunderstorm Warning	GRB	Waushara	43 min
Aug 11, 2:47 PM CDT	Tornado Warning	GRB	Marathon	43 min
Aug 11, 2:51 PM CDT	Severe Thunderstorm Warning	GRB	Brown, Door, Kewaunee	39 min
Aug 11, 2:55 PM CDT	Areal Flood Advisory	GRB	Door	2 hr
Aug 11, 2:58 PM CDT	Special Weather Statement	GRB	Waupaca	47 min
Aug 11, 3:07 PM CDT	Flash Flood Warning	GRB	Marathon	4 hr
Aug 11, 3:08 PM CDT	Severe Thunderstorm Warning	GRB	Outagamie, Shawano, Waupaca	38 min
Aug 11, 3:11 PM CDT	Special Marine Warning	GRB		64 min
Aug 11, 3:29 PM CDT	Severe Thunderstorm Warning Considerable damage threat	GRB	Waushara	18 min
Aug 11, 3:30 PM CDT	Severe Thunderstorm Warning	GRB	Brown, Door, Kewaunee, Oconto, Outagamie, Shawano	60 min
Aug 11, 3:33 PM CDT	Special Marine Warning	GRB		57 min
Aug 11, 3:51 PM CDT	Special Weather Statement	GRB	Outagamie, Winnebago	39 min
Aug 11, 4:05 PM CDT	Special Marine Warning	GRB		55 min

Nearby

Tornado Warnings in Wisconsin, 2021 Every tornado warning in 2021 Tornadoes 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.