Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 30, NWS Green Bay, WI

June 17, 2021Marathon County, Wisconsin

NWS Green Bay, WI issued this severe thunderstorm warning at Jun 17, 2021, 8:02 PM CDT for Marathon County, Wisconsin. It was in force for 18 min. 2 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: Jun 17, 2021, 8:02 PM CDT (01:02 UTC)
Expired: Jun 17, 2021, 8:20 PM CDT
In force: 18 min
Issued by: NWS Green Bay, WI
Area: Storm-based polygon
Hail: 1.25 in
Wind: 60.0 mph

County Marathon County, WI

The radar

The La Crosse radar (KARX), 151 km from the middle of the area, began a volume at 01:04 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.

What was reported inside it

Time	Report	Where	Remark
Jun 17, 8:03 PM CDT	HAIL 1	Colby, WI	VIA WSAW TV-7 FACEBOOK.
Jun 17, 8:04 PM CDT	HAIL 0.75	3 S Abbotsford, WI

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
Jun 17, 3:50 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 00:00Z, 1.0 hours before the alert went out and 168 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: 52 J/kg
Mixed-layer CIN: -285 J/kg
Mixed-layer LCL: 1895 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 310 m²/s²
0-3 km storm-relative helicity: 397 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

As transmitted.

150 
WUUS53 KGRB 180102
SVRGRB
WIC073-180145-
/O.NEW.KGRB.SV.W.0030.210618T0102Z-210618T0145Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Green Bay WI
802 PM CDT Thu Jun 17 2021

The National Weather Service in Green Bay has issued a

* Severe Thunderstorm Warning for...
  Northwestern Marathon County in central Wisconsin...

* Until 845 PM CDT.

* At 801 PM CDT, a severe thunderstorm was located over Colby, or 16
  miles south of Medford, moving east at 45 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.

* This severe thunderstorm will be near...
  Wausau around 835 PM CDT.

Other locations impacted by this severe thunderstorm include Edgar,
Milan, Colby, Cherokee, Unity, Stratford, March Rapids, Marathon
City, Poniatowski and Rib Falls.

This severe thunderstorm replaces the warning already in effect for 
Marathon County. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should move immediately to shelter inside a strong building. 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 4499 9032 4503 9031 4503 8973 4482 8972
      4478 9032
TIME...MOT...LOC 0101Z 262DEG 41KT 4490 9029 

HAIL...1.25IN
WIND...60MPH
 
$$

Eckberg

1 follow-up statement

771 
WWUS53 KGRB 180120
SVSGRB

Severe Weather Statement
National Weather Service Green Bay WI
820 PM CDT Thu Jun 17 2021

WIC073-180130-
/O.CAN.KGRB.SV.W.0030.000000T0000Z-210618T0145Z/
Marathon WI-
820 PM CDT Thu Jun 17 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN MARATHON COUNTY
IS CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled.  However small hail, gusty
winds and heavy rain are still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
central Wisconsin.

LAT...LON 4499 9032 4503 9031 4503 8973 4482 8972
      4478 9032
TIME...MOT...LOC 0119Z 262DEG 41KT 4493 8998 

$$

Eckberg

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 17, 7:09 PM CDT	Severe Thunderstorm Warning	GRB	Marathon, Wood	66 min
Jun 17, 7:29 PM CDT	Special Weather Statement	GRB	Kewaunee	16 min
Jun 17, 9:40 PM CDT	Special Weather Statement	GRB	Brown, Calumet, Manitowoc, Outagamie, Portage, Shawano and 4 more	65 min
Jun 18, 12:29 AM CDT	Special Marine Warning	GRB		83 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.