Severe Thunderstorm Warning 262, NWS Milwaukee, WI

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
713 PM CDT Thu Sep 3 2026

.KEY MESSAGES...

- Periods of showers and storms will be possible through Friday,
  with tonight's round capable of producing strong to severe
  thunderstorms. Damaging winds and heavy rainfall are expected
  to be the main hazards.

- Drier weather expected for the weekend into early next week,
  with warm and humid conditions persisting.

&&

.UPDATE...
Issued 704 PM CDT Thu Sep 3 2026

Rain should hold off this evening, but we are currently
monitoring west central MN as the location where thunderstorms
may develop and then track into Wisconsin during the overnight
hours. Local obs and mesoanalysis data indicate that a primary
and secondary warm front are draped over the UP of Michigan and
through central Wisconsin, respectively, and both connect to an
area of low pressure near Fargo, SD.

Theta-e advection has been noted to be strongest in this area
late this afternoon into the early evening. As a low level jet
kicks in during the overnight hours, the theta-e advection over
the boundaries should increase in strength, leading to more
widespread convective initiation. This convection is then
expected to track ESE along the sfc warm front/CAPE gradient. If
this scenario plays out, the NE half of our CWA would be in line
to see a complex of storms roll through the area between 5am to
8am Friday morning, while the SW half of the CWA sees more hit
or miss storms. Damaging winds would be the main severe weather
hazards, though heavy rain and localized flooding would also be
possible given the high PWATs from 1.8 to 2 inches over the
region, and the high likelihood that storms will track
repeatedly over the same areas overnight into Friday morning.

One potential failure mode or something that could change the
course of the overnight convection is the current convection
that is ongoing over north central WI. This could either push
the instability gradient southward or overturn favorable
instability out ahead of the expected storms. This lends a bit
of uncertainty to the exact track of the storms overnight. These
storms may also arrive in east central Wisconsin sometime this
evening if they hold together.

CMiller

&&

.SHORT TERM...
Issued 326 PM CDT Thu Sep 3 2026

Tonight through Friday night:

We have a surface frontal boundary draped across southern WI
this afternoon. It has not moved much since early this morning.
We have southerly winds and high dewpoints (greater than 72F)
south of a line from the Dells to Watertown to Menomonee Falls,
and a slightly different air mass north of there (dewpoints
67-72 and lighter east-northeast winds). This boundary will
continue to carry a chance for showers and a few thunderstorms
through late evening, despite the meso model forecast reflectivity
field showing that area clear.

Meanwhile, the low level jet will ramp up again this evening and
likely nose all the way into northern WI and the northern
portions of east central WI (between Sheboygan and Green Bay).
This will be our area to watch for scattered thunderstorms to
develop between 8 and 10 PM, and a few could be strong. This
would be in an environment favorable for gusty winds
(downbursts) and hail with modest CAPE and shear. This cluster
of storms is expected to slide southeast and could clip east
central WI including Fond du Lac and Sheboygan.

The storms that just developed and tracked through Grand Forks,
ND this afternoon are what we are watching for our overnight
thunderstorm/severe chances. The broken line of storms should
arrive in central WI around 1 AM (they may catch up or merge
with the LLJ storms in east central WI). The 18Z HRRR is now
tracking this line farther north across northern WI and not
through east central/southeast WI. This might be picking up on a
LLJ and CAPE gradient that is farther north than what the 12Z
models and especially the 06Z models were picking up on.

If this line of storms tracks into southern WI late tonight, it
will exit southeast WI around 8 or 9 AM Friday. Damaging winds
would be the main threat, but we cannot rule out hail or an
isolated tornado. However, the storm motion will slow down
toward morning. With precipitable water values of nearly two
inches and the potential for training storms, heavy rain and
flash flooding will become a larger concern.

If the line misses us, then a stalled outflow boundary will be
one to watch for additional convective development Friday
afternoon (which the HRRR is showing). Timing of
afternoon/evening convection Friday is highly dependent upon how
quickly the morning storms and clouds clear. If there is ample
time with sunny skies, then there is a higher risk for a few
strong/severe storms. Again, damaging winds would be the main
threat with hail and tornado a more isolated threat.

Cronce

&&

.LONG TERM...
Issued 326 PM CDT Thu Sep 3 2026

Saturday through Thursday:

The stalled frontal boundary is expected to get pushed to the
southwest of Wisconsin on Saturday as the upper ridge lifts into
MN and a more amplified trough develops over the eastern Great
Lakes. The frontal boundary may trigger a few showers and storms
(similar location as a lake breeze) midday through evening
Saturday so we are carrying chance pops.

With northeast to easterly winds across all of southern WI on
Sunday and the frontal boundary shunted to our west, we have a
dry forecast on Sunday and Monday. Highs will be much lower
than previous days, ranging from the upper 70s east to the lower
80s west on this holiday weekend.

Our precip chances will return to southern WI Tuesday as the
warm and humid air returns due to low pressure tracking from the
Northern Plains into Ontario. This will be another situation
where a frontal boundary could stall over southern WI and be the
focus for continuous chances for showers/storms through the
rest of the work week.

Cronce

&&

.AVIATION...
Issued 713 PM CDT Thu Sep 3 2026

VFR should persist through the evening, though some lakeshore
terminals may see some marine fog advect inland around 06z in
afterward, introducing some vis restrictions. Thunderstorms are
expected to start as early as 06z in east central WI with their
number/coverage becoming more widespread toward daybreak on
Friday. Ceilings with convection are expected to be between 1500
to 3000 feet. Areas over southwest Wisconsin may miss out on the
lions share of the thunderstorms activity and stay in VFR.

CMiller

&&

.MARINE...
Issued 326 PM CDT Thu Sep 3 2026

A frontal boundary will remain across the Great Lakes region
through Friday. As this frontal boundary waffles north to south
across the lake from day to day, generally east to northeast winds
are expected north of the front, with east to southeast winds
south of the front. On and off thunderstorms will be possible
along and north of this frontal boundary through at least Friday
night. Then high pressure around 30.1 inches builds over Hudson
Bay on Saturday, while low pressure around 29.6 inches moves into
the northern Great Plains. Similar to earlier week storms,
widespread severe weather is not anticipated, though isolated
stronger storms with hail and gusty winds are possible.

Cronce

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...None.
&&

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Hazardous Weather Outlook
National Weather Service Milwaukee/Sullivan WI
641 PM CDT Thu Sep 3 2026

WIZ046-047-051-052-056>060-062>072-042345-
Marquette-Green Lake-Fond du Lac-Sheboygan-Sauk-Columbia-Dodge-
Washington-Ozaukee-Iowa-Dane-Jefferson-Waukesha-Milwaukee-
Lafayette-Green-Rock-Walworth-Racine-Kenosha-
641 PM CDT Thu Sep 3 2026

This Hazardous Weather Outlook is for portions of east central
Wisconsin, south central Wisconsin and southeast Wisconsin.

.DAY ONE...Tonight

Chance for thunderstorms, especially overnight. There is a
potential for strong to severe storms capable of producing
damaging winds. Hail and an isolated tornado are possible as
well.

Locally heavy rainfall with ponding and minor flooding is also
possible with any thunderstorms that move over the same area,
particularly overnight.

.DAYS TWO THROUGH SEVEN...Friday through Thursday

Stalling line of storms Friday morning may produce continued minor
flooding across southern Wisconsin.

Afternoon heat indices in the 90s possible in far southern
Wisconsin Friday.

Isolated to scattered storms Friday afternoon, continuing through
the overnight hours. A few storms may become severe.

A few isolated storms may linger Saturday morning.

Next storm chances develop overnight Monday into Tuesday, with
increasing heat and humidity into Wednesday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed tonight.

LMZ643>646-042345-
Sheboygan to Port Washington WI-
Port Washington to North Point Light WI-
North Point Light to Wind Point WI-
Wind Point WI to Winthrop Harbor IL-
641 PM CDT Thu Sep 3 2026

This Hazardous Weather Outlook is for the nearshore waters from
Sheboygan Wisconsin to Winthrop Harbor Illinois.

.DAY ONE...Tonight

Chance for thunderstorms, especially late tonight. There is a
potential for strong to severe storms capable of producing
damaging winds. Hail and an isolated waterspout are possible as
well.

Some marine fog may also develop overnight

.DAYS TWO THROUGH SEVEN...Friday through Thursday

Isolated to scattered storms Friday afternoon, continuing through
the overnight hours. A few storms may become severe.

A few isolated storms may linger Saturday morning.

Next storm chances develop overnight Monday into Tuesday.

LMZ080-261-362-364-366-563-565-567-669-671-673-675-777-779-868-
870-872-874-876-878-042345-
Lake Michigan Michigan City IN to St. Joseph MI 5 NM offshore to
mid-line of lake.-
Lake Michigan from Seul Choix Point to Rock Island Passage 5NM
offshore to Mid Lake-
Lake Michigan South of a line from Seul Choix Point to the
Mackinac Bridge and North of a line from Charlevoix MI to South
Fox Island 5NM offshore-
Lake Michigan from Charlevoix to Point Betsie MI 5NM Offshore to
mid lake-
Lake Michigan from Point Betsie to Manistee MI 5NM offshore to
Mid Lake-
Lake Michigan from Rock Island Passage to Sturgeon Bay WI 5NM
offshore to mid lake-
Lake Michigan from Sturgeon Bay to Two Rivers WI 5NM offshore to
Mid Lake-
Lake Michigan from Two Rivers to Sheboygan WI 5NM offshore to Mid
Lake-
Lake Michigan from Sheboygan to Port Washington WI 5NM offshore
to Mid Lake-
Lake Michigan from Port Washington to North Point Light WI 5NM
offshore to Mid Lake-
Lake Michigan from North Point Light to Wind Point WI 5NM
offshore to Mid Lake-
Lake Michigan from Wind Point WI to Winthrop Harbor IL 5NM
offshore to Mid Lake-
Lake Michigan from Winthrop Harbor to Wilmette Harbor IL 5NM
offshore to Mid Lake-
Lake Michigan from Wilmette Harbor to Michigan City in 5NM
offshore to Mid Lake-
Lake Michigan from Pentwater to Manistee MI 5NM offshore to Mid
Lake-
Lake Michigan from Whitehall to Pentwater MI 5NM offshore to Mid
Lake-
Lake Michigan from Grand Haven to Whitehall MI 5NM offshore to
Mid Lake-
Lake Michigan from Holland to Grand Haven MI 5NM offshore to Mid
Lake-
Lake Michigan from South Haven to Holland MI 5NM offshore to Mid
lake-
Lake Michigan from St Joseph to South Haven MI 5NM offshore to
Mid Lake-
641 PM CDT Thu Sep 3 2026

This Hazardous Weather Outlook is for the open waters of Lake Michigan.

.DAY ONE...Tonight

Chances for thunderstorms at times today, especially later in the
evening and overnight.

Marine Dense Fog may develop over the middle third of the lake
overnight.

.DAYS TWO THROUGH SEVEN...Friday through Thursday

Isolated to scattered storms Friday afternoon across the southern
half of the lake, continuing through the overnight hours. A few
storms may become severe.

A few isolated storms may linger Saturday morning across the
southern half.

Next storm chances develop overnight Monday into Tuesday across
all of Lake Michigan.

www.weather.gov/mkx

Special Weather Statement
National Weather Service Milwaukee/Sullivan WI
854 PM CDT Thu Sep 3 2026

WIZ046-047-040245-
Green Lake WI-Marquette WI-
854 PM CDT Thu Sep 3 2026

...A STRONG THUNDERSTORM WILL IMPACT NORTHERN GREEN LAKE AND NORTHERN
MARQUETTE COUNTIES THROUGH 945 PM CDT...

At 854 PM CDT, Doppler radar was tracking a strong thunderstorm 7
miles northwest of Wautoma, moving southeast at 45 mph.

HAZARD...Wind gusts up to 45 mph and pea 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...
Berlin, Princeton, Neshkoro, and Springfield Corners.

This includes Interstate 39 between mile markers 115 and 119.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4393 8889 4380 8916 4395 8960 4398 8960
      4398 8889
TIME...MOT...LOC 0154Z 296DEG 37KT 4411 8943

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

KUROSKI

Special Weather Statement
National Weather Service Milwaukee/Sullivan WI
1020 PM CDT Thu Sep 3 2026

WIZ047-051-058-040400-
Dodge WI-Green Lake WI-Fond Du Lac WI-
1020 PM CDT Thu Sep 3 2026

...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN FOND DU LAC...
SOUTHEASTERN GREEN LAKE AND NORTHEASTERN DODGE COUNTIES THROUGH 1100
PM CDT...

At 1020 PM CDT, Doppler radar was tracking a strong thunderstorm near
Brandon, or near Waupun, moving east at 25 mph.

HAZARD...Wind gusts up to 50 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.

Locations impacted include...
Waupun, Mayville, Lomira, Oakfield, Brandon, Lamartine, Byron, Alto,
Brownsville, Fairwater, Kekoskee, Atwater, Oak Center, Lagoda, and
Knowles.

This includes the following highways...
 U.S. Highway 151 between mile markers 140 and 160.
 Interstate 41 between mile markers 89 and 95.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4365 8898 4380 8889 4372 8838 4345 8858
TIME...MOT...LOC 0320Z 286DEG 23KT 4370 8883

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...50 MPH

KUROSKI