Severe Thunderstorm Warning 99, NWS Green Bay, WI

571 
WWUS53 KGRB 020517
SVSGRB

Severe Weather Statement
National Weather Service Green Bay WI
1217 AM CDT Thu Jul 2 2026

WIC015-139-020600-
/O.CON.KGRB.SV.W.0099.000000T0000Z-260702T0600Z/
Calumet WI-Winnebago WI-
1217 AM CDT Thu Jul 2 2026

...SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1 AM CDT FOR
CALUMET AND WINNEBAGO COUNTIES...

At 1217 AM CDT, severe thunderstorms were located along a line from
near Darboy to 15 miles southeast of Rush Lake, or along a line from
5 miles southeast of Appleton to 19 miles south of Oshkosh, moving
east at 40 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

This severe thunderstorm will be near...
  Central Lake Winnebago, Northern Lake Winnebago, High Cliff State
  Park, Appleton and Menasha around 1220 AM CDT. Chilton around 1230
  AM CDT. Brillion and St Anna around 1240 AM CDT.

Other locations impacted by the severe thunderstorm include
Stockbridge, Harrison, Black Wolf Point, Uw Fox Valley, Neenah,
Brothertown, Kloten, Quinney, Sherwood and Jericho.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Seek shelter inside a well-built structure and stay away from
windows. These storms are capable of producing damaging winds.

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

&&

LAT...LON 4405 8867 4424 8866 4424 8804 4413 8804
      4389 8806 4389 8816 4394 8816 4394 8840
      4389 8840 4389 8863 4390 8889 4397 8889
TIME...MOT...LOC 0458Z 270DEG 35KT 4420 8861 4391 8867 4375 8889

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Kurimski

403 
WWUS53 KGRB 020528
SVSGRB

Severe Weather Statement
National Weather Service Green Bay WI
1228 AM CDT Thu Jul 2 2026

WIC015-139-020600-
/O.CON.KGRB.SV.W.0099.000000T0000Z-260702T0600Z/
Calumet WI-Winnebago WI-
1228 AM CDT Thu Jul 2 2026

...SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1 AM CDT FOR
CALUMET AND EASTERN WINNEBAGO COUNTIES...

At 1228 AM CDT, severe thunderstorms were located along a line from 5
miles east of Kaukauna to 10 miles south of Central Lake Winnebago,
or along a line from 11 miles east of Appleton to 14 miles southeast
of Oshkosh, moving east at 55 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

This severe thunderstorm will be near...
  Chilton and Central Lake Winnebago around 1230 AM CDT. Brillion
  around 1235 AM CDT. St Anna around 1240 AM CDT.

Other locations impacted by the severe thunderstorm include Forest
Junction, Jericho, Potter, Hilbert, Brothertown, Dundas, St John,
Brant, Quinney and Kloten.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Seek shelter inside a well-built structure and stay away from
windows. These storms are capable of producing damaging winds.

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

&&

LAT...LON 4389 8865 4400 8849 4424 8847 4424 8804
      4409 8804 4389 8806 4389 8816 4394 8816
      4394 8840 4389 8840
TIME...MOT...LOC 0517Z 250DEG 49KT 4420 8835 4397 8835 4382 8857

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Kurimski

922 
WWUS53 KGRB 020540
SVSGRB

Severe Weather Statement
National Weather Service Green Bay WI
1240 AM CDT Thu Jul 2 2026

WIC015-139-020550-
/O.CAN.KGRB.SV.W.0099.000000T0000Z-260702T0600Z/
Calumet WI-Winnebago WI-
1240 AM CDT Thu Jul 2 2026

...SEVERE THUNDERSTORM WARNING IS CANCELLED FOR CALUMET AND EASTERN
WINNEBAGO COUNTIES...

The storms which prompted the warning have moved out of the area.
Therefore, the Severe Thunderstorm Warning has been cancelled.
However, heavy rain is still possible overnight.

A Severe Thunderstorm Watch remains in effect until 500 AM CDT for a
portion of east central Wisconsin.

&&

LAT...LON 4389 8865 4400 8849 4424 8847 4424 8804
      4409 8804 4389 8806 4389 8816 4394 8816
      4394 8840 4389 8840
TIME...MOT...LOC 0528Z 250DEG 49KT 4425 8816 4402 8816 4387 8838

$$

Kurimski

Area Forecast Discussion
National Weather Service Green Bay WI
635 PM CDT Wed Jul 1 2026

Updated aviation portion for 00Z TAF issuance

.KEY MESSAGES...

- A Heat Advisory is in effect until 8 PM today for east-central
  and far northeast Wisconsin, including the lakeshore counties.
  Additional heat headlines may be needed Thursday.

- Chance for severe weather late this afternoon into tonight with
  potential for damaging straight-line wind gusts, large hail, and
  isolated tornadoes. Isolated flash flooding is also possible.

- Additional chances for thunderstorms through the holiday
  weekend.

&&

.DISCUSSION...
Issued at 249 PM CDT Wed Jul 1 2026

Morning and early convection has largely shifted to the east as of
2PM. Expect a lull in thunderstorm activity across the forecast area
over the next 4-6 hours before the next round of thunderstorms
begins to develop and move into central and east-central WI. This
round of thunderstorms is expected to be focused along a nearly
stationary boundary that that extended from near Green Bay back
toward La Crosse and then toward central IA. A mid-level short-wave
is also evident on water-vapor imagery over western IA and southern
MN. As this short-waves moves east it will be overspreading a highly
unstable environment with dew points in the low to middle 70s and
temperatures quickly warming through the 80s. At 500mb the region is
located under the right rear quad of an 80kt jet streak resulting in
0-6 shear of 40-50kts. This creates a favorable parameter space for
strong to severe thunderstorms capable of producing damaging wind
gusts, large hail, and possible tornados. The tornado threat is
conditional on any storms remain discreet for a period this evening.
As storms grow upscale this may transition a damaging wind event
with 60-80mph wind gusts possible. The window for these higher end
severe hazards is 7PM to midnight. 18Z HRRR also shows convection
reinvigorate overnight as a LLJ noises into central and east-central
WI. This round of storms is very conditional on where this evenings
convection shifts the stationary boundary. If storms do develop
there would be a marginal threat for severe winds and hail.

In addition to the multiple rounds of storms this evening and
overnight, there will is a flooding threat given deep warm cloud
depths and PWATs around 2 inches during times of convection. The
flash flood threat is also conditional on training storms as storms
are expected to be moving quickly to the east, especially if they
develop into a bowing complex.

Models indicate additional convection may develop on Thursday,
however this will depend greatly on the evolution of today/tonight's
convection and where outflow boundaries reside. Latest guidance
would suggest convection developing somewhere from central WI to
southern WI during Thursday afternoon, likely along the instability
gradient. If the strong to severe storms end up in our forecast
area, damaging winds would be the main threat.

The next chance for widespread showers and storms appears to be on
Friday with the passage of the first of multiple mid-level
shortwaves throughout the 4th of July holiday weekend. Timing and
intensity of storms related to this short-wave are highly uncertain.
However, one signal that is persistent for Friday in a round of heavy
rainfall across central and east-central WI as the region remains
under a very humid air mass. Additional rounds of thunderstorms are
possible on Saturday and Sunday, however, however, given the
volatile nature of this air mass it predictability with any
details at this time is low. Beyond Sunday global ensembles and ML
models do trend toward a drier period through the first half of
next week.

Heat/Temperatures...Heat Advisory for central and east-central WI
remains in effect until 8 PM this evening as clearing skies are
quickly leading to rapid warming with temperatures in the low to
middle 80s and heat indices in the middle to upper 90s. A few spots
may near 100 degree heat indices again on Thursday, but will again
depend on thunderstorm activity. For Friday through the holiday
weekend, temperatures and dew points look to slightly decrease, but
will continue to monitor the need for additional heat headlines.

&&

.AVIATION...for 00Z TAF Issuance
Issued at 635 PM CDT Wed Jul 1 2026

Active weather will be the main aviation concern for the early TAF
period through the overnight. Strong to possibly severe
thunderstorms are expected to develop to our west and make their
way into the region through the early evening. Included a
prevailing TSRA group for the best timing of the arrival of
storms, but would expect some rain behind the initial line of
storms. Strongest storms will be capable of producing damaging
wind gusts up to 70 mph, large hail, and isolated tornadoes.
Ending time of active weather remains uncertain, as recent
guidance does suggest the potential for continued rain or a second
round early Thursday morning, so kept this mention in the current
TAFs. Finally, another round of thunderstorms will be possible
Thursday PM, with the strongest storms expected south of a CWA to
GRB line. Amendments will be needed as this severe weather day
progresses given the volatile pattern.

Ahead of these stronger storms inbound from the west at the
beginning of the period, a couple weaker storms are possible for
ATW and MTW as suggested by recent satellite and radar trends
around the TAF issuance. Added a brief TEMPO and PROB 30 for
these areas.

As the showers and storms come to an end sometime late tonight or
towards the end of the TAF period, there are signs of fog
development across north-central WI with MVFR/IFR cigs.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 8 PM CDT this evening for WIZ020>022-031-
037>040-045-048>050-073-074.

Flood Watch through Thursday morning for WIZ020-030-031-035>040-
045-048>050-074.
&&

DISCUSSION.....GK
AVIATION.......Uhlmann

Hazardous Weather Outlook
National Weather Service Green Bay WI
252 PM CDT Wed Jul 1 2026

WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074-022000-
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-
252 PM CDT Wed Jul 1 2026

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

.DAY ONE...Tonight

Heat Advisories for east-central and far northeast Wisconsin,
including the lakeshore areas is in effect until 8 PM today,
where heat index values up to 100 degrees are forecast.

Multiple rounds of thunderstorms are expected late this afternoon
into tonight and may result in a higher-end severe risk with the
potential for damaging straight-line winds over 70 mph, hail up to
golf-ball size, and isolated tornadoes. Isolated flash flooding is
also possible.

.DAYS TWO THROUGH SEVEN...Thursday through Wednesday

Daytime heat index values will be near 100 degrees on Thursday,
especially over east-central Wisconsin. A Heat Advisory may be
needed.

Periodic chances for thunderstorms will continue through the
holiday weekend. A few storms on Thursday could be strong to
severe. Heavy rain could also occur.

.SPOTTER INFORMATION STATEMENT...

Spotters are requested to report peak wind gusts, hail, and any
flooding to the National Weather Service in Green Bay. Spotter
activation may be needed on Thursday.

LMZ521-522-541>543-022000-
The Bay of Green Bay south of a line from Cedar River MI to Rock
Island Passage-Lake Michigan from Washington Island to Sheboygan-
252 PM CDT Wed Jul 1 2026

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

.DAY ONE...Tonight

There is a chance for thunderstorms through tonight. Some storms
may become severe with damaging straight-line wind gusts and large
hail. Any thunderstorm would pose a hazard to mariners.

.DAYS TWO THROUGH SEVEN...Thursday through Wednesday

Periodic chances for thunderstorms will continue through the
holiday weekend. Storms occurring Thursday could be strong to
severe. Any thunderstorm would pose a hazard to mariners.

GK

Special Weather Statement
National Weather Service Green Bay WI
726 PM CDT Wed Jul 1 2026

WIZ050-020045-
Manitowoc WI-
726 PM CDT Wed Jul 1 2026

...A STRONG THUNDERSTORM WILL IMPACT NORTHEASTERN MANITOWOC COUNTY
THROUGH 745 PM CDT...

At 726 PM CDT, Doppler radar was tracking a strong thunderstorm near
Two Creeks, or 9 miles north of Manitowoc, moving east at 40 mph.

HAZARD...Wind gusts up to 30 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...
  Two Creeks around 730 PM CDT.

Other locations impacted by this storm include Mishicot, Fisherville,
Larrabee, Point Beach Nuclear Plant, Shoto, Francis Creek, and Two
Rivers.

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 4427 8775 4435 8748 4431 8748 4416 8753
      4416 8770
TIME...MOT...LOC 0026Z 256DEG 34KT 4423 8766

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...30 MPH

Eckberg

Special Weather Statement
National Weather Service Green Bay WI
905 PM CDT Wed Jul 1 2026

WIZ035>037-045-020300-
Waupaca WI-Portage WI-Wood WI-Waushara WI-
905 PM CDT Wed Jul 1 2026

...AN AREA OF STRONG THUNDERSTORMS WILL IMPACT NORTHWESTERN
WAUSHARA...SOUTHERN PORTAGE...SOUTHWESTERN WAUPACA AND WOOD COUNTIES
UNTIL 10 PM CDT...

At 905 PM CDT, Doppler radar was tracking an area of strong
thunderstorms extending from over Plainfield to 32 miles southwest of
Spencer, or extending from 12 miles northwest of Wautoma to 44 miles
west of Wisconsin Rapids, moving east at 35 mph.

HAZARD...Half inch size hail.

SOURCE...Radar indicated.

IMPACT...Minor damage to outdoor objects is possible.

The strong thunderstorms will be near...
  Plainfield around 905 PM CDT. Babcock around 915 PM CDT. Pittsville
  and Wisconsin Rapids around 935 PM CDT. Chain O' Lakes-King, Lake
  Wazeecha and Waupaca around 940 PM CDT. Hartman Creek State Park
  around 945 PM CDT. Amherst, Whiting and Stevens Point around 955 PM
  CDT.

Other locations impacted by these strong thunderstorms include
Hancock, Sandhill Wildlife Area, Heffron, Almond, Cranmoor, Scranton,
Dexterville, Veedum, Nekoosa and Walker.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the weather situation closely and be alert for threatening
weather conditions.

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

&&

LAT...LON 4461 9032 4440 8893 4400 8957 4401 8960
      4425 8960 4425 9032
TIME...MOT...LOC 0204Z 249DEG 31KT 4420 8946 4421 9007 4440 9072

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...<30 MPH

JLA

Special Weather Statement
National Weather Service Green Bay WI
1021 PM CDT Wed Jul 1 2026

WIZ038-039-048>050-020400-
Calumet WI-Brown WI-Manitowoc WI-Winnebago WI-Outagamie WI-
1021 PM CDT Wed Jul 1 2026

...A LINE OF STRONG THUNDERSTORMS WILL IMPACT NORTHERN CALUMET...
NORTHEASTERN WINNEBAGO...SOUTHEASTERN OUTAGAMIE...NORTHWESTERN
MANITOWOC AND BROWN COUNTIES UNTIL 11 PM CDT...

At 1021 PM CDT, Doppler radar was tracking a line of strong
thunderstorms extending from 8 miles southwest of Green Bay to 7
miles southwest of Menasha, or extending from 8 miles southwest of
Green Bay to 10 miles north of Oshkosh, moving east at 30 mph.

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

SOURCE...Radar indicated.

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

The strong thunderstorm will be near...
  Appleton, Menasha, Kaukauna, Little Chute, Kimberly, Darboy,
  Northern Lake Winnebago, High Cliff State Park and Brillion around
  1025 PM CDT. Bellevue around 1030 PM CDT.

Other locations impacted by this strong thunderstorm include De Pere,
Greenleaf, Holland, Askeaton, Neenah, Dundas, Ledgeview, Allouez,
Lambeau Field and Greenville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the weather situation closely and be alert for threatening
weather conditions.

&&

LAT...LON 4407 8874 4436 8858 4455 8822 4466 8776
      4459 8776 4443 8777 4422 8777
TIME...MOT...LOC 0320Z 249DEG 24KT 4442 8810 4426 8816 4417 8855

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

Kurimski