Severe Thunderstorm Warning 21, NWS Green Bay, WI

502 
WWUS53 KGRB 140101
SVSGRB

Severe Weather Statement
National Weather Service Green Bay WI
801 PM CDT Mon Apr 13 2026

WIC097-115-135-140130-
/O.CON.KGRB.SV.W.0021.000000T0000Z-260414T0130Z/
Portage WI-Waupaca WI-Shawano WI-
801 PM CDT Mon Apr 13 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 830 PM CDT
FOR NORTHEASTERN PORTAGE...NORTHERN WAUPACA AND WESTERN SHAWANO
COUNTIES...

At 800 PM CDT, a severe thunderstorm was located near Embarrass, or 
10 miles west of Shawano, moving east at 35 mph. Another severe 
thunderstorm was located near Big Falls.

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.

Locations impacted include...
Shawano, Clintonville, Embarrass, Stockton, Belle Plaine, Red River,
Marion, Pella, Tigerton, and Gresham.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 1000 PM CDT for central and
northeastern Wisconsin.

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4450 8948 4466 8940 4468 8933 4468 8922
      4472 8922 4487 8873 4479 8859 4460 8861
TIME...MOT...LOC 0100Z 263DEG 30KT 4472 8879 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.25 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

KScharf

309 
WWUS53 KGRB 140128
SVSGRB

Severe Weather Statement
National Weather Service Green Bay WI
828 PM CDT Mon Apr 13 2026

WIC097-115-135-140138-
/O.EXP.KGRB.SV.W.0021.000000T0000Z-260414T0130Z/
Portage WI-Waupaca WI-Shawano WI-
828 PM CDT Mon Apr 13 2026

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN PORTAGE...
NORTHERN WAUPACA AND WESTERN SHAWANO COUNTIES WILL EXPIRE AT 830 PM
CDT...

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 will be allowed to expire.  However, gusty
winds and heavy rain are still possible with this thunderstorm.

A Tornado Watch remains in effect until 1000 PM CDT for central and
northeastern Wisconsin.

&&

LAT...LON 4450 8948 4466 8940 4468 8933 4468 8922
      4472 8922 4487 8873 4479 8859 4460 8861
TIME...MOT...LOC 0128Z 250DEG 34KT 4481 8845 

$$

KScharf

Area Forecast Discussion
National Weather Service Green Bay WI
244 PM CDT Mon Apr 13 2026

.KEY MESSAGES...

- Thunderstorms will develop late this afternoon and continue
  into the overnight hours with hail in excess of 2 inches,
  damaging winds and a tornado possible with the strongest
  storms. The highest risk is across central Wisconsin.

- Rainfall amounts of 1 to 3 inches across parts of central into
  east-central Wisconsin may lead to additional flood concerns
  through tonight.

- An active stretch of weather continues through late week with
  continued periods of showers and storms. The risk area for
  severe storms shifts south on Tuesday, but extends north into
  parts of central and east-central Wisconsin.

- Minor to moderate river flooding is ongoing or forecast to
  occur on several area rivers. Expect many rivers to rise this
  week due to additional rain and runoff from Upper Michigan,
  with the greatest impacts expected on the Menominee River,
  where some locations may see major flooding during the mid to
  late part of the week.

&&

.DISCUSSION...
Issued at 245 PM CDT Mon Apr 13 2026

Tonight: Severe Storms/Heavy Rain

Early afternoon surface analysis indicated a surface low over
central Nebraska with a warm front snaking eastward across
northern Iowa into central Wisconsin. MLCAPE has increased to
around 1000 J/kg across central Wisconsin with some inhibition
noted.

Late this afternoon, expect more focused storm
initiation/intensification generally in the vicinity of the
warm front and nose of the low- level jet. Surface-based
instability is maximized over central Wisconsin (1000-2000 J/kg)
by late this afternoon with effective shear around 40-50 kts.
Combined with steep lapse rates already sampled by the 18Z GRB
RAOB, the environment will be supportive of large to very large
hail. The tornado risk likely will be highest along the warm
front from west-central Wisconsin into perhaps central
Wisconsin as the low-level jet increases early this evening and
overlaps the warm front/instability axis. Damaging wind risk
will depend on the degree of upscale growth/organization of
storms. Overall, the severe weather risk lessens with northward
extent.

Precipitable water values remain near the top of climatology for
mid April. HREF probability matched mean 24-hr rainfall is in
the 1 to 3 inch range across parts of central into east-central
Wisconsin through tonight, on the nose of the low-level jet.
However, rainfall amounts will depend on the organization and
degree of training. This rainfall could exacerbate already
saturated soils.

Areas of fog may also develop overnight behind the storms.

Tuesday: Additional storms

The front slides south on Tuesday with the instability axis also
displaced south. The placement of the boundary will impact the
northward extent of severe weather during the
afternoon/evening. RAP hodographs show lesser low-level shear
although an elongated profile favorable for large hail and
winds. Currently the highest risk of severe storms is across
southern Wisconsin, but could extend into parts of east-central
Wisconsin.

Wednesday-Monday: Active into the weekend

Southwest flow aloft persists into late week keeping the area in
a warm, wet pattern. Another shortwave trough will bring
additional shower (40-80%) chances Wednesday into Thursday. A
more dynamic trough is slated to impact the region late Friday
into the weekend bringing additional widespread rainfall and
storms. The northward extent of greater instability is somewhat
uncertain with this system, impacting severe weather potential,
but this will be something to watch in the coming days. Drier
and cooler weather is expected behind this system for early next
week.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1251 PM CDT Mon Apr 13 2026

Widespread showers and storms will develop late this afternoon
into the overnight hours with MFVR/IFR conditions. Initial
storms may begin to initiate by 21-22Z today, becoming more
widespread this evening. Areas of fog/low clouds will likely
persist into Tuesday.

&&

.HYDROLOGY...
Issued at 245 PM CDT Mon Apr 13 2026

Flooding is expected to continue on several area rivers during
the week, and will be exacerbated by periodic heavy rainfall.
Runoff from Upper Michigan is still expected to bring moderate
to major flooding along the Menominee River, especially during
the mid to late part of the week. If you live near a river or
stream, keep a close eye on water levels this week and monitor
the latest Flood Warnings from the National Weather Service in
Green Bay.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
WI...Flood Watch through Tuesday morning for WIZ013-018>022-030-031-
     035>040-045-048>050-073-074.
MARINE...None.

&&

DISCUSSION...JM
AVIATION...JM
HYDROLOGY...Kieckbusch/JM

Hazardous Weather Outlook
National Weather Service Green Bay WI
251 PM CDT Mon Apr 13 2026

WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074-142000-
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-
251 PM CDT Mon Apr 13 2026

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

.DAY ONE...Tonight

Elevated water levels or flooding continue along some rivers.

Severe storms, including heavy rainfall, large to very large hail,
damaging winds and tornado or two are possible late this afternoon
into tonight. The highest risk of severe storms is across central
into east- central Wisconsin.

Additional flooding may occur for areas that receive heavy
rainfall tonight.

.DAYS TWO THROUGH SEVEN...Tuesday through Monday

There is a chance of severe thunderstorms south of a line from
Wisconsin Rapids to Sturgeon bay during the late afternoon and
evening on Tuesday. Large hail and strong winds will be the
primary threats.

Additional thunderstorms are possible Wednesday afternoon into
Wednesday night, and again Friday night into Saturday.

Elevated water levels and at least minor flooding will continue
along many rivers through the week. Runoff from the Upper
Peninsula will likely result in moderate to possibly major flooding
on the Menominee River during the mid to late part of the week.

.SPOTTER INFORMATION STATEMENT...

Spotters should report severe weather and flooding to the
National Weather Service in Green Bay.

LMZ521-522-541>543-142000-
The Bay of Green Bay south of a line from Cedar River MI to Rock
Island Passage-Lake Michigan from Washington Island to Sheboygan-
251 PM CDT Mon Apr 13 2026

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

.DAY ONE...Tonight

Thunderstorms, some possibly strong to severe, are expected
tonight.

Areas of fog are possible.

.DAYS TWO THROUGH SEVEN...Tuesday through Monday

Thunderstorms will be possible at times Tuesday through Wednesday
night, and again Friday night into Saturday. Severe storms will
be possible Tuesday evening.

Preliminary Local Storm Report
National Weather Service Green Bay WI
641 PM CDT Mon Apr 13 2026

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

0608 PM     Hail             5 NE Marshfield         44.71N 90.10W
04/13/2026  E1.25 Inch       Marathon           WI   Public

&&

Preliminary Local Storm Report
National Weather Service Green Bay WI
709 PM CDT Mon Apr 13 2026

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

0637 PM     Hail             2 ESE Peru              44.55N 89.20W
04/13/2026  M1.25 Inch       Waupaca            WI   Amateur Radio

&&

Preliminary Local Storm Report
National Weather Service Green Bay WI
726 PM CDT Mon Apr 13 2026

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

0714 PM     Hail             Clintonville            44.61N 88.75W
04/13/2026  M0.50 Inch       Waupaca            WI   Trained Spotter

&&

Special Weather Statement
National Weather Service Green Bay WI
730 PM CDT Mon Apr 13 2026

WIZ039-074-140100-
Southern Oconto County WI-Brown WI-
730 PM CDT Mon Apr 13 2026

...A STRONG THUNDERSTORM WILL IMPACT NORTHWESTERN BROWN AND SOUTHERN
OCONTO COUNTIES THROUGH 800 PM CDT...

At 730 PM CDT, Doppler radar was tracking a strong thunderstorm near
Green Bay, moving northeast at 45 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...
  Green Bay around 735 PM CDT.

Other locations impacted by this storm include Anston, Stiles,
Sobieski, Kunesh, South Chase, Pensaukee, Lambeau Field, Chase,
Hobart, and Leo Frigo Bridge.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Tornado Watch remains in effect until 1000 PM CDT for northeastern
Wisconsin.

&&

LAT...LON 4447 8819 4459 8819 4459 8824 4496 8811
      4487 8777 4486 8777 4471 8792 4463 8793
      4467 8783 4442 8804
TIME...MOT...LOC 0030Z 205DEG 39KT 4453 8811

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

KScharf

Special Weather Statement
National Weather Service Green Bay WI
736 PM CDT Mon Apr 13 2026

WIZ031-036-037-140100-
Waupaca WI-Shawano WI-Portage WI-
736 PM CDT Mon Apr 13 2026

...A STRONG THUNDERSTORM WILL IMPACT NORTHEASTERN PORTAGE...
NORTHWESTERN WAUPACA AND WESTERN SHAWANO COUNTIES THROUGH 800 PM
CDT...

At 736 PM CDT, Doppler radar was tracking a strong thunderstorm 10
miles southeast of Bevent, or 18 miles northeast of Stevens Point,
moving east at 40 mph.

HAZARD...Wind gusts of 50 to 55 mph and penny 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.

Locations impacted include...
Stevens Point, Whiting, Plover, Stockton, Marion, Pella, Tigerton,
Jordan, Rosholt, and Bowler.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Tornado Watch remains in effect until 1000 PM CDT for central and
northeastern Wisconsin.

&&

LAT...LON 4464 8951 4468 8942 4468 8923 4478 8922
      4491 8896 4476 8875 4457 8884 4448 8954
TIME...MOT...LOC 0036Z 250DEG 34KT 4465 8923

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...55 MPH

KScharf

Preliminary Local Storm Report
National Weather Service Green Bay WI
738 PM CDT Mon Apr 13 2026

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

0729 PM     Hail             2 WNW Ashwaubenon       44.50N 88.11W
04/13/2026  M0.50 Inch       Brown              WI   NWS Employee

0734 PM     Hail             2 W Howard              44.56N 88.09W
04/13/2026  M0.50 Inch       Brown              WI   Public

&&