Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 45, NWS Green Bay, WI

May 27, 2026Marathon County, Wisconsin

NWS Green Bay, WI issued this severe thunderstorm warning at May 27, 2026, 4:36 PM CDT for Marathon County, Wisconsin. It was in force for 39 min. 8 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
May 27, 2026, 4:36 PM CDT (21:36 UTC)
Expired
May 27, 2026, 5:15 PM CDT
In force
39 min
Issued by
NWS Green Bay, WI
Area
Storm-based polygon
Hail
1.5 in
Wind
60.0 mph

County Marathon County, WI

The radar

The Green Bay radar (KGRB), 129 km from the middle of the area, began a volume at 21:40 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
May 27, 4:37 PM CDTHAIL 21 E Rib Mountain State, WIReport from mPING: Hen Egg (2.00 in.).
May 27, 4:46 PM CDTHAIL 1.252 E Evergreen, WIReport from mPING: Half Dollar (1.25 in.).
May 27, 4:48 PM CDTHAIL 1.252 E Evergreen, WIReport from mPING: Half Dollar (1.25 in.).
May 27, 4:49 PM CDTHAIL 1.252 E Evergreen, WIReport from mPING: Half Dollar (1.25 in.).
May 27, 4:50 PM CDTTSTM WND DMG1 Nw Mosinee, WISeveral trees down at River Park in Mosinee. Time estimated by radar. Report from WSAW-TV.
May 27, 4:50 PM CDTHAIL 1.252 E Evergreen, WIReport from mPING: Half Dollar (1.25 in.).
May 27, 4:51 PM CDTHAIL 1.252 Se Rothschild, WIReport from mPING: Half Dollar (1.25 in.).
May 27, 4:59 PM CDTTSTM WND GST 451 Ese Mosinee, WIMeasured at the Central WI Airport.

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

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched 7 storm reports to this severe thunderstorm warning; the first came 1 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 9.6 hours before the alert went out and 309 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, Minneapolis, MN at 12:00Z on 2026-05-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 146 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, Minneapolis, MN at 12:00Z on 2026-05-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 28 square meters per square second.193958Sfc1 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
146 J/kg
Mixed-layer CIN
-272 J/kg
Mixed-layer LCL
1326 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
28 m²/s²
0-3 km storm-relative helicity
22 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The text

As transmitted.

646 
WUUS53 KGRB 272136
SVRGRB
WIC073-272215-
/O.NEW.KGRB.SV.W.0045.260527T2136Z-260527T2215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Green Bay WI
436 PM CDT Wed May 27 2026

The National Weather Service in Green Bay has issued a

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

* Until 515 PM CDT.

* At 435 PM CDT, a severe thunderstorm was located near Mosinee, or
  10 miles south of Wausau, moving south at 25 mph.

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

  SOURCE...Radar indicated. This storm has a history of producing 
           hail up to golf ball size.

  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...
  Mosinee around 440 PM CDT.

Other locations impacted by this severe thunderstorm include Peplin,
Camp Phillips Scout Camp, Moon, Schofield, Rocky Corners, Rib
Mountain State Park, Knowlton, Evergreen, and Rothschild.

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 4494 8976 4494 8957 4469 8945 4469 8984
TIME...MOT...LOC 2135Z 347DEG 19KT 4482 8962 

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

$$

KLJ
3 follow-up statements
676 
WWUS53 KGRB 272148
SVSGRB

Severe Weather Statement
National Weather Service Green Bay WI
448 PM CDT Wed May 27 2026

WIC073-272215-
/O.CON.KGRB.SV.W.0045.000000T0000Z-260527T2215Z/
Marathon WI-
448 PM CDT Wed May 27 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 515 PM CDT
FOR SOUTH CENTRAL MARATHON COUNTY...

At 447 PM CDT, a severe thunderstorm was located near Mosinee, or 14
miles south of Wausau, moving south at 25 mph.

HAZARD...Golf ball size hail and 60 mph wind gusts.

SOURCE...Radar indicated. This storm has a history of producing ping 
         pong ball size hail.

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 remain over mainly rural areas of south
central Marathon County, including the following locations... Peplin,
Knowlton, Moon, Evergreen, Rocky Corners, and Rothschild.

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 4487 8978 4486 8953 4469 8945 4469 8984
TIME...MOT...LOC 2147Z 348DEG 20KT 4475 8963 

TORNADO...POSSIBLE
THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

KLJ
576 
WWUS53 KGRB 272157
SVSGRB

Severe Weather Statement
National Weather Service Green Bay WI
457 PM CDT Wed May 27 2026

WIC073-272215-
/O.CON.KGRB.SV.W.0045.000000T0000Z-260527T2215Z/
Marathon WI-
457 PM CDT Wed May 27 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 515 PM CDT
FOR SOUTH CENTRAL MARATHON COUNTY...

At 457 PM CDT, a severe thunderstorm was located 7 miles southeast of
Mosinee, or 12 miles north of Stevens Point, moving south at 20 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...
Mosinee, Knowlton, Peplin, Moon, and Rocky Corners.

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 4481 8980 4482 8951 4469 8945 4469 8984
TIME...MOT...LOC 2157Z 347DEG 19KT 4470 8961 

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

$$

KLJ
244 
WWUS53 KGRB 272213
SVSGRB

Severe Weather Statement
National Weather Service Green Bay WI
513 PM CDT Wed May 27 2026

WIC073-272222-
/O.EXP.KGRB.SV.W.0045.000000T0000Z-260527T2215Z/
Marathon WI-
513 PM CDT Wed May 27 2026

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL MARATHON COUNTY
WILL EXPIRE AT 515 PM CDT...

The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.  However, heavy 
rain, localized flooding, and small hail is still possible with this 
thunderstorm.

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

&&

LAT...LON 4481 8980 4482 8951 4469 8945 4469 8984
TIME...MOT...LOC 2212Z 347DEG 19KT 4464 8959 

$$

KLJ

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Green Bay, WI wrote its last area forecast discussion before this severe thunderstorm warning went out at May 27, 1:54 PM CDT, 2 hours 42 minutes earlier. Its key messages:

  • Isolated to scattered thunderstorms are possible for the rest of the afternoon and early evening. A few storms could become strong to severe with damaging winds and hail, especially in central WI and the western Fox Valley between 4 pm and 8 pm.
  • Conditions hazardous to small craft are expected tonight for the Lake Michigan nearshore waters south of Sturgeon Bay. Boaters should exercise caution on the bay of Green Bay this evening.
  • There is a high risk for rip currents tonight for beaches along Lake Michigan in Manitowoc County.
  • Mainly dry weather with above normal temperatures and low relative humidity for the next week, with highs mainly in the middle 70s to middle 80s.
Area forecast discussion, May 27, 1:54 PM CDT, 2 hours 42 minutes before
Area Forecast Discussion
National Weather Service Green Bay WI
154 PM CDT Wed May 27 2026

Forecast discussion for routine afternoon forecast issuance

.KEY MESSAGES...

- Isolated to scattered thunderstorms are possible for the rest of
  the afternoon and early evening. A few storms could become
  strong to severe with damaging winds and hail, especially in
  central WI and the western Fox Valley between 4 pm and 8 pm.

- Conditions hazardous to small craft are expected tonight for
  the Lake Michigan nearshore waters south of Sturgeon Bay.
  Boaters should exercise caution on the bay of Green Bay this
  evening.

- There is a high risk for rip currents tonight for beaches along
  Lake Michigan in Manitowoc County.

- Mainly dry weather with above normal temperatures and low
  relative humidity for the next week, with highs mainly in the
  middle 70s to middle 80s.

&&

.DISCUSSION...
Issued at 153 PM CDT Wed May 27 2026

A back door cold front over northern WI will shift south across
the region this afternoon and early evening. Scattered showers
have already developed along the boundary. CAMs continue to show
thunderstorms initiating along the boundary by around 20z,
spreading south through the rest of afternoon, then exiting our
southern counties in the early evening. The arrival of cooler and
drier air behind the cold front and E-NE winds off Lake Michigan
will limit instability in northern and eastern WI, with better
instability (SBCAPE 1000-1500) expected over central WI and the
western Fox Valley. This is also the area where DCAPE calues are
currently highest (800-1000 j/kg). With Effective bulk shear
increasing to around 30 kts near the cold front, ingredients are
in place for a few strong to severe storms, especially in central
WI and the western Fox Valley. Damaging winds and hail will be the
primary threats.

The front should shift south of the region early this evening,
bringing a period of gusty northeast winds to the Fox Valley and
lakeshore areas, a period of high waves to our southernmost Lake
Michigan marine zones, and a high threat of rip currents for
Manitowoc County beaches. A Beach Hazards Statement has been
issued from this evening through early Thursday morning for
Manitowoc County.

Canadian high pressure and an Omega Block pattern will bring
a long stretch of mainly dry weather. Right now, only small
precipitation chances are expected with a back door cold front
late Sunday into Sunday night.

Ttemperatures will average well above normal through much of the
period, with highs mainly in the mid 70s to mid 80s. Low afternoon
relative humidity could lead to elevated fire weather conditions,
but green-up continues across northern WI and pine fuels have
become less volatile, so impacts may not be as significant as they
would have been a couple weeks ago.

&&

.AVIATION...for 18Z TAF Issuance
Issued at 1237 PM CDT Wed May 27 2026

A cold front was generating scattered showers across far northern
WI early this afternoon. As this front shifts south this
afternoon, showers and scattered thunderstorms will develop along
it. a few of the storms could become strong to severe, with
damaging winds and hail the primary threats. Most of this
activity should shift south of the region by early evening. Have
added TEMPO groups for storms at AUW/CWA/ATW, where the better
moisture and instability will be present, but only mentioned
Prob30 for the TAF sites farther north and east. After the storms
end, expect skies to clear.

As the front passes by early this evening, gusty northeast winds
are likely to develop for a 3-6 hour period. Gusts up to 25 kts
will be possible over the northeast WI terminals, especially at
KGRB and KMTW. The stronger gusts should subside overnight.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Beach Hazards Statement from 9 PM CDT this evening through late
tonight for WIZ050.
&&

DISCUSSION.....Kieckbusch
AVIATION.......Kieckbusch
Hazardous weather outlook, May 27, 2:00 PM CDT, 2 hours 36 minutes before
Hazardous Weather Outlook
National Weather Service Green Bay WI
200 PM CDT Wed May 27 2026

WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074-281900-
Vilas-Oneida-Forest-Florence-Northern Marinette County-Lincoln-
Langlade-Menominee-Northern Oconto County-Door-Marathon-Shawano-
Wood-Portage-Waupaca-Outagamie-Brown-Kewaunee-Waushara-Winnebago-
Calumet-Manitowoc-Southern Marinette County-
Southern Oconto County-
200 PM CDT Wed May 27 2026

This Hazardous Weather Outlook is for north-central and northeast
Wisconsin.

.DAY ONE...Rest of this Afternoon and Tonight

Scattered thunderstorms are possible for the rest of this
afternoon and early evening, except across far northern and
eastern Wisconsin. A few storms could become strong to severe with
damaging winds and hail, especially over central Wisconsin and
the western Fox Valley between 4 pm and 8 pm.

There is a high risk for rip currents tonight for beaches along
Lake Michigan in Manitowoc County.

.DAYS TWO THROUGH SEVEN...Thursday through Wednesday

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotters are requested to report any wind damage or hail to the
National Weather Service in Green Bay.

LMZ521-522-541>543-281900-
The Bay of Green Bay south of a line from Cedar River MI to Rock
Island Passage-Lake Michigan from Washington Island to Sheboygan-
200 PM CDT Wed May 27 2026

This Hazardous Weather Outlook is for portions of northwest Lake
Michigan and the waters of Green Bay.

.DAY ONE...Tonight

Isolated thunderstorms are possible for the rest of this
afternoon. Any thunderstorms would pose a hazard to mariners.

Gusty northeast winds will bring conditions hazardous to small
craft tonight to the Lake Michigan nearshore waters south of
Sturgeon Bay. A Small Craft Advisory is in effect. The gusty winds
also mean boaters should exercise caution on the bay of Green Bay
this evening.

.DAYS TWO THROUGH SEVEN...Thursday through Wednesday

The probability for widespread hazardous weather is low.

Kieckbusch

In the hours before

Special weather statement, May 27, 2:56 PM CDT, 1 hour 40 minutes before
Special Weather Statement
National Weather Service Green Bay WI
256 PM CDT Wed May 27 2026

WIZ010-018-019-272030-
Langlade WI-Oneida WI-Lincoln WI-
256 PM CDT Wed May 27 2026

...A STRONG THUNDERSTORM WILL IMPACT NORTHEASTERN LINCOLN...SOUTH
CENTRAL ONEIDA AND NORTHWESTERN LANGLADE COUNTIES THROUGH 330 PM
CDT...

At 256 PM CDT, Doppler radar was tracking a strong thunderstorm near
Rhinelander, moving southeast at 30 mph.

HAZARD...Wind gusts up to 40 mph and nickel size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor hail damage to vegetation is
         possible.

This strong thunderstorm will be near...
  Parrish around 315 PM CDT.

Other locations impacted by this storm include Crescent Corner, Kelly
Lynn Bog Natural Area, and Jeffris.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4559 8953 4564 8946 4542 8921 4534 8943
TIME...MOT...LOC 1956Z 326DEG 25KT 4555 8943

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...40 MPH

KLJ
Special weather statement, May 27, 3:15 PM CDT, 1 hour 21 minutes before
Special Weather Statement
National Weather Service Green Bay WI
315 PM CDT Wed May 27 2026

WIZ018-019-030-272100-
Langlade WI-Marathon WI-Lincoln WI-
315 PM CDT Wed May 27 2026

...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN LINCOLN...EASTERN
MARATHON AND SOUTHWESTERN LANGLADE COUNTIES THROUGH 400 PM CDT...

At 314 PM CDT, Doppler radar was tracking a strong thunderstorm near
Dutch Corners, or 14 miles northeast of Wausau, moving southeast at
30 mph.

HAZARD...Wind gusts up to 40 mph and nickel size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor hail damage to vegetation is
         possible.

This storm will remain over mainly rural areas of southeastern
Lincoln, eastern Marathon and southwestern Langlade Counties,
including the following locations... Ringle, Glandon, Ackley Wildlife
Area, Schofield, Nutterville, Otis, Hatley, Sunset, Camp Phillips
Scout Camp, and Gleason.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

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

&&

LAT...LON 4540 8960 4503 8917 4503 8922 4495 8922
      4475 8959 4525 8989
TIME...MOT...LOC 2014Z 325DEG 27KT 4515 8950

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...40 MPH

KLJ
Local storm report, May 27, 4:36 PM CDT, 0 minutes before
Preliminary Local Storm Report
National Weather Service Green Bay WI
436 PM CDT Wed May 27 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0410 PM     Hail             3 NW Wausau             44.98N 89.67W
05/27/2026  E0.88 Inch       Marathon           WI   Public

0412 PM     Hail             1 WSW Wausau            44.96N 89.64W
05/27/2026  M1.00 Inch       Marathon           WI   Trained Spotter

0415 PM     Hail             3 NW Rib Mountain State 44.95N 89.72W
05/27/2026  M1.00 Inch       Marathon           WI   Public

0416 PM     Hail             1 SSE Wausau            44.95N 89.62W
05/27/2026  M1.50 Inch       Marathon           WI   Broadcast Media

            Reported at WSAW-TV.

0416 PM     Hail             2 N Wausau              44.99N 89.63W
05/27/2026  M1.00 Inch       Marathon           WI   Trained Spotter

0417 PM     Hail             1 NW Rib Mountain State 44.93N 89.68W
05/27/2026  E1.25 Inch       Marathon           WI   Public

            Report from mPING: Half Dollar (1.25 in.).

0419 PM     Hail             3 NW Rib Mountain State 44.96N 89.69W
05/27/2026  M1.00 Inch       Marathon           WI   Public

0419 PM     Hail             1 SSE Wausau            44.95N 89.62W
05/27/2026  M1.00 Inch       Marathon           WI   Broadcast Media

            Quarter size hail at the Wausau Downtown
            Airport.

0420 PM     Hail             1 E Wausau              44.96N 89.61W
05/27/2026  M1.50 Inch       Marathon           WI   Trained Spotter

0420 PM     Hail             2 NW Schofield          44.92N 89.62W
05/27/2026  E0.75 Inch       Marathon           WI   Public

            Report from mPING: Dime (0.75 in.).

0422 PM     Hail             2 W Rib Mountain        44.90N 89.71W
05/27/2026  E0.50 Inch       Marathon           WI   Public

            Report from mPING: Half-inch (0.50 in.).

0425 PM     Hail             1 SW Schofield          44.89N 89.60W
05/27/2026  M1.00 Inch       Marathon           WI   Public

0429 PM     Hail             1 SW Rib Mountain       44.90N 89.70W
05/27/2026  E0.50 Inch       Marathon           WI   Public

            Report from mPING: Half-inch (0.50 in.).

&&

The office that day

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

IssuedProductOfficeCountiesLasted
May 27, 1:00 AM CDTBeach Hazards StatementGRBManitowoc26 hr
May 27, 1:00 AM CDTSmall Craft AdvisoryGRB26 hr
May 27, 2:56 PM CDTSpecial Weather StatementGRBOneida34 min
May 27, 3:15 PM CDTSpecial Weather StatementGRBMarathon45 min
May 27, 3:27 PM CDTSevere Thunderstorm WarningGRBLanglade, Lincoln, Marathon48 min
May 27, 3:59 PM CDTSevere Thunderstorm WarningGRBMarathon46 min
May 27, 5:00 PM CDTSevere Thunderstorm WarningGRBPortage30 min
May 27, 5:13 PM CDTAreal Flood AdvisoryGRBMarathon3 hr
May 27, 5:19 PM CDTSevere Thunderstorm WarningGRBMarathon26 min
May 27, 5:26 PM CDTSevere Thunderstorm WarningGRBPortage49 min
May 27, 5:43 PM CDTSpecial Weather StatementGRBWood32 min
May 27, 6:46 PM CDTSpecial Weather StatementGRBWaushara44 min
May 27, 6:55 PM CDTSevere Thunderstorm WarningGRBWaushara20 min

Nearby

Severe Thunderstorm Warnings in Wisconsin, 2026Every severe thunderstorm warning in 2026

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.