Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2025

Severe Thunderstorm Warning 94, NWS Green Bay, WI

August 9, 20254 counties in Wisconsin

NWS Green Bay, WI issued this severe thunderstorm warning at Aug 9, 2025, 1:11 PM CDT for 4 counties in Wisconsin. It was in force for 36 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Aug 9, 2025, 1:11 PM CDT (18:11 UTC)
Expired: Aug 9, 2025, 1:47 PM CDT
In force: 36 min
Issued by: NWS Green Bay, WI
Area: Storm-based polygon
Tornado: Possible
Hail: 0.75 in
Wind: 60.0 mph

Counties Portage County, WI, Waupaca County, WI, Waushara County, WI, Winnebago County, WI

The radar

The Green Bay radar (KGRB), 81 km from the middle of the area, began a volume at 18:15 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.

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 12:00Z, 6.2 hours before the alert went out and 82 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: 1553 J/kg
Mixed-layer CIN: -152 J/kg
Mixed-layer LCL: 1070 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 105 m²/s²
0-3 km storm-relative helicity: 80 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

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 Aug 9, 11:59 AM CDT, 1 hour 12 minutes earlier.

Area forecast discussion, Aug 9, 11:59 AM CDT, 1 hour 12 minutes before

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Hazardous weather outlook, Aug 9, 11:06 AM CDT, 2 hours 5 minutes before

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In the hours before

Special weather statement, Aug 9, 8:33 AM CDT, 4 hours 38 minutes before

Special Weather Statement
National Weather Service Green Bay WI
833 AM CDT Sat Aug 9 2025

WIZ010-011-019-020-030-031-091400-
Shawano WI-Langlade WI-Marathon WI-Oneida WI-Forest WI-Menominee WI-
833 AM CDT Sat Aug 9 2025

...STRONG THUNDERSTORMS WILL IMPACT SOUTHWESTERN FOREST...EASTERN
MARATHON...SOUTHEASTERN ONEIDA...NORTHWESTERN MENOMINEE...LANGLADE
AND WESTERN SHAWANO COUNTIES THROUGH 900 AM CDT...

At 833 AM CDT, Doppler radar was tracking a cluster of strong
thunderstorms along a line extending from 11 miles east of
Rhinelander to near Bevent. Movement was east at 20 mph.

HAZARD...Wind gusts up to 40 mph and half inch hail.

SOURCE...Radar indicated.

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

Strong thunderstorms will be near...
  Antigo, Wittenberg, and Veterans Memorial County Park around 840
  AM CDT.

Other locations impacted by these storms include Gagen, Lake Noseum,
Aniwa, Popple River Headwaters Natural Area, Elderon, Mattoon, Pike
Lake, Post Lake, Polar, and Kempster.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

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

Frequent cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 4468 8895 4468 8944 4567 8926 4581 8876
TIME...MOT...LOC 1333Z 261DEG 19KT 4563 8920 4473 8935

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH

JLA

Local storm report, Aug 9, 10:29 AM CDT, 2 hours 42 minutes before

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Special weather statement, Aug 9, 12:13 PM CDT, 58 minutes before

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Special weather statement, Aug 9, 12:18 PM CDT, 53 minutes before

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Local storm report, Aug 9, 12:59 PM CDT, 12 minutes before

Preliminary Local Storm Report
National Weather Service Green Bay WI
1259 PM CDT Sat Aug 9 2025

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

1210 PM     Hail             De Pere                 44.45N 88.05W
08/09/2025  M0.50 Inch       Brown              WI   Public

&&

Special weather statement, Aug 9, 1:00 PM CDT, 11 minutes before

Special Weather Statement
National Weather Service Green Bay WI
100 PM CDT Sat Aug 9 2025

WIZ073-074-091845-
Southern Oconto County WI-Southern Marinette County WI-
100 PM CDT Sat Aug 9 2025

...STRONG THUNDERSTORMS WILL IMPACT SOUTHERN MARINETTE AND SOUTHERN
OCONTO COUNTIES THROUGH 145 PM CDT...

At 1259 PM CDT, Doppler radar was tracking a cluster of strong
thunderstorms near Oconto, or 15 miles northwest of Bay Shore Park,
moving northeast at 35 mph.

HAZARD...Wind gusts up to 40 mph and half inch 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...
  Oconto around 105 PM CDT.

Other locations impacted by this storm include Little Suamico,
Cullen, Abrams, Brookside, Stiles, County Line, Harmony, Peshtigo,
Sobieski, and Pensaukee.

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.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 4494 8759 4490 8778 4486 8777 4470 8792
      4467 8797 4474 8816 4512 8782 4498 8757
TIME...MOT...LOC 1759Z 225DEG 30KT 4482 8796

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH

JLA

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 9, 7:13 AM CDT	Special Weather Statement	GRB	Lincoln, Marathon, Oneida	62 min
Aug 9, 7:33 AM CDT	Severe Thunderstorm Warning	GRB	Langlade, Lincoln, Marathon, Oneida	42 min
Aug 9, 8:20 AM CDT	Special Weather Statement	GRB	Forest	40 min
Aug 9, 8:33 AM CDT	Special Weather Statement	GRB	Langlade	27 min
Aug 9, 9:28 AM CDT	Flood Watch	GRB	Brown, Calumet, Kewaunee, Manitowoc, Outagamie, Portage and 4 more	7 hr
Aug 9, 10:53 AM CDT	Areal Flood Advisory	GRB	Langlade, Lincoln, Marathon, Menominee, Portage, Shawano and 1 more	3 hr
Aug 9, 12:13 PM CDT	Special Weather Statement	GRB	Portage, Wood	62 min
Aug 9, 12:18 PM CDT	Special Weather Statement	GRB	Brown	42 min
Aug 9, 1:00 PM CDT	Special Weather Statement	GRB	Oconto	45 min
Aug 9, 1:03 PM CDT	Special Marine Warning	GRB		57 min
Aug 9, 1:44 PM CDT	Special Weather Statement	GRB	Waupaca	31 min
Aug 9, 1:56 PM CDT	Severe Thunderstorm Warning	GRB	Outagamie, Shawano, Waupaca	34 min
Aug 9, 2:06 PM CDT	Severe Thunderstorm Warning	GRB	Brown, Door, Kewaunee	39 min
Aug 9, 2:16 PM CDT	Severe Thunderstorm Warning	GRB	Brown, Oconto, Outagamie, Shawano, Waupaca	44 min
Aug 9, 2:20 PM CDT	Special Weather Statement	GRB	Calumet, Winnebago	40 min
Aug 9, 2:30 PM CDT	Special Marine Warning	GRB		60 min
Aug 9, 2:32 PM CDT	Severe Thunderstorm Warning	GRB	Brown, Calumet, Outagamie, Winnebago	43 min
Aug 9, 2:34 PM CDT	Special Marine Warning	GRB		66 min
Aug 9, 2:40 PM CDT	Severe Thunderstorm Warning	GRB	Brown, Kewaunee	50 min
Aug 9, 2:42 PM CDT	Tornado Warning	GRB	Brown, Calumet	10 min
Aug 9, 2:56 PM CDT	Severe Thunderstorm Warning	GRB	Brown, Kewaunee, Manitowoc, Oconto	34 min
Aug 9, 3:24 PM CDT	Special Weather Statement	GRB	Manitowoc	51 min
Aug 9, 3:24 PM CDT	Special Weather Statement	GRB	Kewaunee	51 min
Aug 9, 3:28 PM CDT	Special Marine Warning	GRB		62 min
Aug 9, 3:32 PM CDT	Special Marine Warning	GRB		118 min
Aug 9, 3:35 PM CDT	Special Marine Warning	GRB		25 min
Aug 9, 3:46 PM CDT	Severe Thunderstorm Warning	GRB	Door	44 min

Nearby

Severe Thunderstorm Warnings in Wisconsin, 2025 Every severe thunderstorm warning in 2025

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.