Severe Thunderstorm Warning 92, NWS Green Bay, WI

Area Forecast Discussion
National Weather Service Green Bay WI
Issued by National Weather Service Milwaukee/Sullivan WI
300 PM CDT Wed Jul 23 2025

.KEY MESSAGES...

- Periods of showers and thunderstorms this afternoon into
  Thursday evening, especially for areas north of HWY-10. Strong
  to severe storms will be possible with damaging winds and
  heavy rainfall being the main concerns late this afternoon and
  evening.

- Heavy rainfall expected through tonight for areas northwest
  of a line from Menominee to Wisconsin Rapids. 1 to 2 inches
  will be possible along the front, but locally higher amounts
  approaching 3 to 4 inches will not be out of the question.
  Flood watch has been issued for northwest WI counties until
  Thursday morning.

- Hot and humid this afternoon, especially south of HWY-10 as
  heat indices climb into the upper 90s to around 100F.

- Not as warm Friday and Saturday, then warmer Sunday into
  Monday with highs reaching the upper 80s to around 90. Chances
  for showers and storms at times through the weekend into early
  next week.

&&

.DISCUSSION...
Issued at 256 PM CDT Wed Jul 23 2025

Short Term...This Afternoon...Tonight...and Thursday

The MCV that brought scattered showers this morning continues
to lift east-northeast across northeastern WI. Clouds do linger
in its wake, but gradually seeing a clearing trend from the
southwest. Will see temps and dewpoints continue to increase as
the clouds clear through the remainder of the the afternoon.
While the warmup has been delayed and heat indices are slower to
climb, do still expect a few hour window during peak heating
(3-5pm) this afternoon for areas along and south of HWY-10 to
climb to around 100F. Thus will maintain the Heat Advisory
through this evening.

Otherwise focus is on the afternoon and evening thunderstorm
potential. There are a couple of areas to keep an eye on. First
areas is the remnant MCV. While the 12z-14z CAMs such as the
HRRR and ARW were trying to develop isolated thunderstorms along
the MCV moving across the area, latest radar/satellite
observations show this feature already through much of
northeastern WI and should be east of the area by the mid
afternoon. Thus, cannot completely rule out an isolate storm
east of I-43, generally not expecting this scenario to pan out
as the forcing will exit before the instability is able to build
into the area.

The second area will be along the warm front lifting northward
across the region this afternoon. This will bring in higher
dewpoints in the mid 70s, clearing skies, and warmer temps
helping building up the instability. Latest SPC/RAP analysis
shows a strong CAPE gradient along the front with SBCAPE values
up to 4000-5000 J/kg. The latest radar observations show
upstream convection across central MN and west-northwest WI and
it will not take much to get additional development, especially
with any remnant outflow boundaries front the upstream
convection riding the warm front eastward. While overall deep
layer (0-6km)/effective shear looks modest (<30kt), cannot rule
out see some taller storms to develop, which could be capable of
producing damaging winds gusts and if isolated enough maybe
even some hail approaching severe limits. Will need to monitor
upstream activity as this scenario for a line of strong to
severe storms is starting to look like it may materialize and
move into areas west of I-39 corridor. The best potential will
be over the next few hours into this evening for areas northwest
of a line from Menominee to Wisconsin Rapids.

The other concern will the slow moving nature of this activity
along with efficient rainfall rates. PWATs currently exceed 2
inches and this juicy environment is not expected to diminish
anytime soon. HREF is pinging a swath of 1-2 inches along the
boundary this afternoon and overnight with 24hr probability
match mean hinting at locally higher amounts approaching 3-4
inches for northwestern portions of the area. Thus have elected
to issue a Flood Watch for west-northwest portions of the CWA
for Vila, Oneida, Lincoln, Langlade, and Marathon counties this
afternoon through Thursday morning.

For Thursday the warm moist airmass remains in place overnight
into Thursday as main/longwave trough swings across Upper
Midwest. This will kick off the progression of cold front from
the northwoods southeastward across the state early Thursday
morning through much of the day. While not expecting much at
this time given the overnight activity, cannot rule out
additional development into Thursday morning. Timing will be key
as it looks to move through during the first half of the day.
So may not be enough time for instability to build for
widespread stronger storms on Thursday. However, cannot rule out
areas across east-central WI to see some additional
development, but the better potential remains further southeast.

Long Term...Friday Through Tuesday

More zonal upper-level flow will set up across the Upper
Midwest for Friday with surface high pressure setting up across
Lake Superior to Lake Michigan region. This will bring not as
hot and drier conditions with highs in the lower to mid 80s and
cooler along the lakeshore for Friday. Overnight lows look to
dip down into low to mid 60s. However, southerly flow returns to
the area into Saturday as the high skirts eastward and as a
mid-level shortwave trough and broad surface low lifts into the
Upper Midwest from the Central Plains. While looking warmer on
Saturday, the latest 12z mid-range models are tracking a broad
surface low/trough across central WI and keeping much of the
area on the north side of the system. Given this solution, the
better rain/shower chances will be across southern portions of
the state, with more of a glancing chance for central and east
central WI. Low and mid-level trough looks to quickly push east
overnight into Sunday with southerly flow, warmer temps, and
moisture quickly return ahead of another mid-level shortwave
trough traversing across the Upper Midwest. Still uncertainty on
strength and timing of this next wave, but will be another
opportunity for some increased shower and thunderstorm chances.
Early next week will see a similar pattern with a series of
shortwave trough trekking through every other day or so. This
would bring periodic shower and storm chances through middle of
next week along with bouts of very warm, above normal temps and
humid conditions.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 256 PM CDT Wed Jul 23 2025

for 18Z TAF Issuance
Issued at 1256 PM CDT Wed Jul 23 2025

Precipitation trends will be the main concern for the TAF period,
with a warm front lifting northwards through the afternoon and
the a passing cold front this evening through tomorrow.

Initial MCV from this morning has largely progressed
northeastwards this morning, diminishing through the afternoon and
leaving some scattered high clouds as the warm front progresses
northwards. For east-central TAF sites including OSH, this will
allow for a quieter period with VFR skies and returning sunshine,
although the return of some lower cumulus clouds is possible as
the afternoon heats up. Further west for AUW, CWA and north for
RHI, active weather along the aforementioned warm front will bring
back rain and thunder early in the TAF period, as well as keeping
some MVFR to brief IFR ceilings. Storms and rain should progress
northwards by mid afternoon, returning some quieter conditions to
AUW and CWA for a time before attention returns to additional
convection in the evening.

As we get towards the evening, a passing cold front will bring
additional storms and showers into portions of central and north-
central Wisconsin, with some potential for severe weather,
especially further north. As this system passes, it is expected to
continue progressing mostly northeastwards, which should bypass
much of east-central Wisconsin including GRB, ATW, and OSH through
the early overnight period, but some southern development is
possible. Current thinking is this will still miss the Fox Valley
and east-central, but may need to reassess if storms dive
considerably further southwards in the early overnight period.
Finally, some re-initiation of active weather will be possible
across east-central Wisconsin in the late morning on Thursday, so
a PROB30 was included for this across east-central Wisconsin,
which includes OSH.

Winds will be gusty through the period, with gusts up to 20 knots
at times in the afternoon and evening. As winds drop off at the
surface tonight, some LLWS will be possible for most TAF sites.
Winds will become gusty again late tomorrow morning as well,
shifting from the south to the southwest.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
WI...Flood Watch through Thursday morning for WIZ005-010-018-019-
     030.
     Beach Hazards Statement through late tonight for WIZ022.
     Heat Advisory until 8 PM CDT this evening for WIZ035>039-045-
     048>050.
     Beach Hazards Statement until 1 AM CDT Thursday for WIZ040-050.
MARINE...Small Craft Advisory until 4 AM CDT Thursday for LMZ541.
     Small Craft Advisory until 1 AM CDT Thursday for LMZ542-543.

&&

DISCUSSION...KW
AVIATION...JM

Hazardous Weather Outlook
National Weather Service Green Bay WI
Issued by National Weather Service Milwaukee/Sullivan WI
304 PM CDT Wed Jul 23 2025

WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074-242015-
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-
304 PM CDT Wed Jul 23 2025

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

.DAY ONE...Tonight

Scattered thunderstorms are expected at times this afternoon and
evening with strong to severe storms capable of damaging winds
are possible, mainly across northern Wisconsin.

Heavy rainfall expected, along with a potential for flash
flooding within any thunderstorms through the evening and
overnight. A Flood Watch has been issued for Northwest and north-
central WI.

Heat indices of 95 to 102 degrees are expected late this afternoon
for portions of central and east-central Wisconsin where a Heat
Advisory is in effect.

A high swim risk is expected through late this evening for the
Lake Michigan beaches of Door, Kewaunee, and Manitowoc counties. A
Beach Hazard Statement is in effect.

.DAYS TWO THROUGH SEVEN...Thursday through Wednesday

Thunderstorms and heavy rainfall are possible Thursday into
Thursday evening. A few storms may become strong. Additional
chances for thunderstorms are possible Saturday and Monday.

Hot and humid conditions are possible, especially early next
week.

.SPOTTER INFORMATION STATEMENT...

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

LMZ521-522-541>543-242015-
The Bay of Green Bay south of a line from Cedar River MI to Rock
Island Passage-Lake Michigan from Washington Island to Sheboygan-
304 PM CDT Wed Jul 23 2025

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

.DAY ONE...Tonight

Thunderstorms are expected at times. Any thunderstorms will pose a
threat to mariners.

Persistent southerly winds will create conditions hazardous to
small craft along the Lake Michigan nearshore waters through late
this evening. A Small Craft Advisory is in effect.

.DAYS TWO THROUGH SEVEN...Thursday through Wednesday

Thunderstorms are expected on Thursday. Additional chances for
thunderstorms are possible Saturday and Monday.

Preliminary Local Storm Report
National Weather Service Green Bay WI
516 PM CDT Wed Jul 23 2025

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

0500 PM     Tstm Wnd Dmg     7 N Iola                44.60N 89.11W
07/23/2025                   Waupaca            WI   Trained Spotter

&&

Preliminary Local Storm Report
National Weather Service Green Bay WI
548 PM CDT Wed Jul 23 2025

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

0516 PM     Tstm Wnd Dmg     Keshena                 44.88N 88.64W
07/23/2025                   Menominee          WI   Emergency Mngr

            Report from Menominee Tribe Emergency
            manager trees and power lines down. Cause of
            damage will be reviewed.

&&

JF

Preliminary Local Storm Report
National Weather Service Green Bay WI
557 PM CDT Wed Jul 23 2025

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

0516 PM     Tstm Wnd Dmg     Rosholt                 44.63N 89.31W
07/23/2025                   Portage            WI   Trained Spotter

            Trees and power lines down.

&&

JF

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>