980
FXUS63 KMKX 281551
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1051 AM CDT Sat Jun 28 2025

.KEY MESSAGES...

- Heat index vales in the 95 to 100 degree range are expected on
  Sunday.

- Thunderstorms are possible Sunday afternoon and evening,
  along and ahead of a cold front. Gusty winds are possible with
  the strongest storms.

- Turning a little less humid through the middle of next week,
  with a more active weather pattern returning toward the end
  of the week.

&&

.UPDATE...
Issued 1051 AM CDT Sat Jun 28 2025

Weak sfc high pressure over eastern Wisconsin and Lake Michigan
have brought mostly clear skies to much of the area. Low clouds
have scattered out with a few high level clouds continuing to
stream through from the northwest.

Watching the ongoing rain showers to our northwest in southern
Minnesota this morning. The small chance (around 10% or less)
for our western counties to get clipped by this decaying system
still exists. These chances may continue to decrease if the rate
of decay continues at the rate its at and the overall movement
of this system keeps it to our north. CAMs are starting to show
that scenario a bit more. Overall, sky cover was the only major
change this morning due to the clearer conditions. Upped temps
by a degree or two, but clouds should briefly return this
evening.

Patterson

&&

.SHORT TERM...
Issued 357 AM CDT Sat Jun 28 2025

Today through Sunday night:

Some fog may develop across south central Wisconsin into the
early morning hours, with light to calm winds and small dewpoint
depressions. Confidence is low at this time, as there are some
lingering clouds in the 2500 to 3500 foot AGL range that may
limit this possibility over areas around and north of Madison.

In addition, there is some high clouds from the convection in
the Northern Plains that may move into the area into this
morning. This may also limit fog development. The best chances
will be in the Wisconsin River Valley and other low-lying areas.

The low clouds may linger into the rest of the morning, before
moving to the east or mixing out. The high clouds should be thin
enough to allow for partial sunshine by late morning or
afternoon, with diurnal cumulus clouds developing. Highs should
get into the middle 80s inland, with southeast winds near the
lake keeping highs in the middle to upper 70s.

Some CAMs try to bring remnants of the convection southeast
toward or into western portions of the area by middle to late
afternoon. The low level jet should remain focused more to the
northwest and north into today, so think any weakening showers
and storms would remain in those areas. For now, kept forecast
dry for this afternoon in the west.

The low level jet remains focused to the north and northwest of
the area tonight into Sunday morning, so most of the showers
and storms associated with it should remain to the northwest and
north. Kept small PoPs (20 percent) in far northwestern and
western parts of the area later tonight into Sunday morning,
just in case any remnant showers and storms hold together.

It should be a very warm and humid day on Sunday, with 925 mb
temperatures supporting highs around 90 degrees. Dewpoints in
the lower 70s should bring heat index values into the 95 to 100
degree range for Sunday afternoon. The forecast heat index
values are near the 90th to 95th percentile per the NBM, so no
heat headlines will be issued at this time. Still, it will be a
muggy day, so that will need to be messaged.

CAMs are varying with timing and placement of showers and
storms for Sunday afternoon into the evening. They generally
develop along the weak cold front from central to southwest
Wisconsin into northeast Iowa by middle to late afternoon
Sunday. They should gradually work into south central Wisconsin
by early Sunday evening.

However, some CAMs have the activity weakening during the
evening, with others dry for the area. The frontogenesis is
robust, if it moves through the area. There are not much other
features to help generate showers and storms besides a possible
MCV feature from earlier convection to the west. Thus, forecast
confidence remains low with what may occur during this period.

There will be plenty of instability to work with, with mean
layer CAPE above 2000 J/kg but with weak deep layer bulk shear
of 10 to 15 knots. Thus, some gusty winds may occur with
stronger storms and perhaps some hail. For now, will continue
to monitor this storm potential for Sunday afternoon and
evening, and hopefully gain some confidence in timing and
impacts in later forecasts.

Wood

&&

.LONG TERM...
Issued 357 AM CDT Sat Jun 28 2025

Monday through Friday:

The precip forecast is uncertain for Monday, as it will depend
on how Sunday plays out. If a remnant outflow boundary stalls
over southern Wisconsin Sunday night, this may act as a focus
area for shower and storm development on Monday, once the
clouds clear out. Temperatures will depend on our cloud cover,
but the dewpoints are expected to remain on the higher side.

We will wait for the next upper trough to swing across the
Upper Midwest and Great Lakes Monday afternoon and night in
order to kick out some of the warmth and humidity.

Drier conditions will move in Tuesday in the form of slightly
lower dewpoints, but our temperatures may not drop much. This
will hold through Wednesday.

The upper ridge over the west will start to lean over into
southwest Wisconsin Thursday into Independence Day. This puts
us in a favorable position to receive a round or two of
convection, as storms fire upstream and ride the ridge through
central or southern Wisconsin. This may be very similar to this
past week.

Cronce

&&

.AVIATION...
Issued 1051 AM CDT Sat Jun 28 2025

Mostly clear skies across southern Wisconsin late this morning
through the afternoon. The low level clouds this morning have
scattered out leaving a few clouds around 3kft moving east out
of the state. There are some high level clouds moving through as
well, but there should be a brief period of clear skies for all
of southern Wisconsin. Additional clouds will move in from the
west later this afternoon into this evening. These clouds will
be from a decaying system in Minnesota, no rain is expected here
and clouds will be around 10 15 kft. Terminals in southeast
Wisconsin may not see many of these clouds.

Light south to southwest winds for inland areas. A lake breeze
is expected to move inland so lakeshore terminals will see there
light and variable winds become southeast to easterly by this
afternoon. As weak high pressure moves east out of the state
winds across the region will become southeast which will help
the lake breeze move farther inland. Light southerly winds will
continue through tonight before becoming more southwesterly and
increasing a bit Sunday.

Patterson

&&

.MARINE...
Issued 357 AM CDT Sat Jun 28 2025

Weak high pressure around 30.0 inches over the region will move
east today, leading to light to modest west winds becoming
south to southeast. Winds will become south and increase
Saturday night into Sunday, as the high moves east of the
region. A cold front will then move east across the region later
Sunday night into Monday, with winds shifting to the west.
Showers and some thunderstorms may accompany the frontal
passage. The west winds should linger into the middle of next
week.

Wood

&&

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

$$

Visit us at weather.gov/milwaukee

Follow us on Facebook, Twitter, and YouTube at:
www.facebook.com/NWSMilwaukee
www.twitter.com/NWSMilwaukee
www.youtube.com/NWSMilwaukee