Severe Thunderstorm Warning 101, NWS Green Bay, WI

Area Forecast Discussion
National Weather Service Green Bay WI
113 PM CDT Wed Jul 8 2026

Forecast discussion for routine afternoon forecast issuance

.KEY MESSAGES...

- Scattered strong to severe thunderstorms remain expected this
  afternoon and evening, mainly between 3 and 8 PM over central
  and east-central Wisconsin. Damaging winds are the primary
  threat.

- Torrential rainfall rates of 2 to 3 inches per hour within the
  strongest storms will create a risk for localized flash
  flooding, especially in urban, low-lying, and poorly drained
  areas.

- Trends continue to be monitored for the excessive heat potential
  early next week.

&&

.DISCUSSION...
Issued at 112 PM CDT Wed Jul 8 2026

The latest RAP analysis and satellite/radar imagery show a cold
front stretching from west-central to north-central Wisconsin
early this afternoon. Morning showers and storms have exited over
northern Lake Michigan, giving way to partial clearing across
central and east-central Wisconsin where temperatures have warmed
into the lower 80s. Cooler temperatures in the lower to middle 70s
persist across the north where cloud cover and rainfall were more
widespread. Cloud cover is becoming more extensive again over
southern Minnesota in association with a remnant MCV. Focus of
this forecast remains on the severe weather and flash flooding
potential through this evening.

Severe Weather and Flood Outlook:  Destabilization is actively
taking place early this afternoon over central and east-central
Wisconsin where mixed- layer CAPE is climbing upwards of 1000
J/kg. With further solar heating, thunderstorms are expected to
redevelop in a buoyant airmass south of the front and across
central Wisconsin in the 18-20Z time frame. These storms should
track east through the afternoon before propagating southeast this
evening as a cold pool becomes established. Deep layer shear of
25 to 35 knots is expected in the area of greatest concern across
central and east- central Wisconsin. This shear profile will be
supportive of a few bowing structures and perhaps an isolated
supercell. Given the modest shear aloft, conditions will be most
favorable for damaging wind gusts rather than severe hail. High
freezing levels around 15,000 feet and poor mid-level lapse rates
do not favor large hail, except within the strongest rotating
updrafts. A weak, isolated tornado will also be possible, most
likely focused along an outflow boundary or lake breeze where low-
level vorticity is enhanced. The greatest period of concern is
from 3 to 7 PM before storms shift south and east of the forecast
area. Scattered shower and storm activity could persist into the
overnight period, but a stabilizing atmosphere should keep
intensities below severe levels.

Upper-level flow will be nearly parallel to the surface front
within a corridor of precipitable water values approaching 2.00
inches and high freezing levels. High rainfall rates of 2 to 3
inches per hour are expected in the strongest storms, which could
lead to localized flash flooding in vulnerable urban, low-lying,
and poorly drained areas.

Fog Potential Late Tonight:  After the rain winds down late
tonight into Thursday morning, there is a decent signal for fog
development, particularly across central to north-central
Wisconsin where clearing will occur first. Considerable
uncertainty exists regarding how long showers stick around into
Thursday. A moist boundary layer, weak cyclonic flow in the low
levels, and weak shortwave impulses aloft could keep light showers
lingering into the afternoon over central and east- central
Wisconsin.

Excessive Heat Outlook: An amplified upper air pattern featuring
a dominant upper- level ridge is expected to build northeast into
the region Friday through the weekend and persist into early next
week.

High pressure at the surface will slide across the area
Friday through the weekend. While minor signals for spotty shower
activity exist in some medium-range guidance, forcing is non-
existent beneath the building ridge, and a dry forecast has been
maintained.

The primary story in the extended period will be potential for
excessive heat. Very warm air aloft will accompany the building
ridge will argue for surface high temperatures climbing into the
upper 80s to lower 90s by Monday and Tuesday. Coupled with
humidities remaining high, minor heat- related impacts appear
possible at this time for those outdoors. Some relief from the
heat and humidity is expected towards the middle to end of the
next work week as the ridge begins to suppress southward.

&&

.AVIATION...for 18Z TAF Issuance
Issued at 1153 AM CDT Wed Jul 8 2026

Late this morning, a cold front stretches from west-central
Wisconsin to north-central Wisconsin. MVFR to IFR ceilings exist
along and north of the front while VFR conditions prevail to the
south and south of RHI.

This front will provide the focus for clusters of showers and
storms this afternoon and evening. Thunderstorm redevelopment is
expected 19-20Z with impacts into RHI/AUW/CWA starting during this
timeframe. These storms are expected to increase in coverage and
proceed into the Fox Valley in the 22-23Z period. Strong storms
are likely with gusts in excess of 40 mph possible with ceilings
and visibilities falling to MVFR and IFR/LIFR respectively.
After the initial push of storms, scattered showers with embedded
thunder looking to continue through much of the evening, while
light showers could persist across parts of central and east-
central WI into Thu morning.

Late tonight, there is a decent signal for ground fog to develop.
Central and north-central WI have potential for sub-IFR
visibilities. The fog should lift into a MVFR stratus deck after
about 15Z.

Winds will be light over the period.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
None.

&&

DISCUSSION.....MPC
AVIATION.......MPC

Hazardous Weather Outlook
National Weather Service Green Bay WI
115 PM CDT Wed Jul 8 2026

WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074-091815-
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-
115 PM CDT Wed Jul 8 2026

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

.DAY ONE...Tonight

Strong to severe thunderstorms are possible between 3 and 8 PM,
mainly across central and east-central Wisconsin. Damaging winds
is the primary risk, although small hail and an isolated tornado
are also possible.

Favorable conditions for localized flash flooding will exist
this afternoon and evening. Rainfall rates as high as 2-3" per
hour could create urban flooding, ponding of water on roadways,
and rising water levels in ditches, creeks and rivers.

Patchy dense fog will restrict visibilities over north-central
Wisconsin late tonight.

.DAYS TWO THROUGH SEVEN...Thursday through Wednesday

There is a chance of thunderstorms on Thursday. Severe weather is
not expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotters will likely be needed this afternoon into the evening,
especially across central and east-central WI. Spotters are
requested to report wind gusts over 40 mph, wind damage and any
localized flooding.

LMZ521-522-541>543-091815-
The Bay of Green Bay south of a line from Cedar River MI to Rock
Island Passage-Lake Michigan from Washington Island to Sheboygan-
115 PM CDT Wed Jul 8 2026

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

.DAY ONE...Tonight

Thunderstorms are possible late this afternoon and tonight. Some
of the storms will be capable of producing strong winds and hail,
along with localized visibilities below one mile in heavy rain.

.DAYS TWO THROUGH SEVEN...Thursday through Wednesday

There is a small chance of a thunderstorm on Thursday south of
Manitowoc.

MPC

Special Weather Statement
National Weather Service Green Bay WI
210 PM CDT Wed Jul 8 2026

WIZ030-036-081945-
Portage WI-Marathon WI-
210 PM CDT Wed Jul 8 2026

...A STRONG THUNDERSTORM WILL IMPACT NORTHEASTERN PORTAGE AND
SOUTHEASTERN MARATHON COUNTIES UNTIL 245 PM CDT...

At 210 PM CDT, Doppler radar was tracking a strong thunderstorm near
Stevens Point, moving east at 25 mph.

HAZARD...Wind gusts up to 40 mph and nickel 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...
  Stevens Point and Whiting around 210 PM CDT.

Other locations impacted by this strong thunderstorm include Jordan,
Park Ridge, Dewey Marsh Wildlife Area, Stockton, Ellis, Polonia,
North Star, Custer, Shantytown and Nelsonville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4450 8963 4465 8964 4471 8944 4474 8923
      4457 8922 4449 8922
TIME...MOT...LOC 1909Z 265DEG 21KT 4458 8949

MAX HAIL SIZE...0.88 IN
MAX WIND GUST...40 MPH

GK