503
FXUS63 KMKX 060308
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1008 PM CDT Sat Jul 5 2025

.KEY MESSAGES...

- Lingering showers with an isolated thunderstorm or two late
  this evening diminishing overnight into Sunday morning. Could
  see additional storms in southeast WI Sunday afternoon.

- Increasing northeasterly winds and building waves will result
  in dangerous swimming conditions along Lake Michigan beaches
  sunday afternoon into MOnday morning. High swim risk for
  Milwaukee, racine, and kenosha counties, while moderate swim
  risk for Sheboygan and Ozaukee county beaches.

- Humidity returns Tuesday through the end of the week, with
  periods of showers and thunderstorms also returning.

&&

.UPDATE...
Issued 1005 PM CDT Sat Jul 5 2025

Line of showers with an isolated rumble of thunder continue to
diminish as they work their way across southeastern WI this
evening. The upstream line of showers crossing the Mississippi
River Valley continues to weaken and fall apart as we lose
daytime heating and support. Expecting this trend to continue
and see it dissipate more as it moves into our CWA in the next
hour or two. However, scattered light to moderate showers will
be possible through the remainder of the early into the early
morning hours. Otherwise, could see some shower and storm
redevelopment along the front in southeast WI Sunday afternoon,
but overall potential remains limited given lack of forcing.

Main update this evening is the issuance of the beach hazard
statement for dangerous current developing along southeastern WI
beaches later Sunday afternoon into Monday morning. High swim
risk will be for Milwaukee, racine, and Kenosha county beaches
where waves are progged to build up to 4 to 6 feet. Northern
exposed beaches, piers, and breakwalls will be the most
vulnerable to these dangerous currents. Waves will be a bit less
further north in Sheboygan and Ozaukee counties, but still
expected moderate swim risk during this time as well.

Wagner

&&

.SHORT TERM...
Issued 307 PM CDT Sat Jul 5 2025

Tonight and Sunday:

Low pressure system has advanced eastward toward the Upper
Peninsula of Michigan this afternoon. As the sfc low moves east
so to does the upper level trough/wave bringing some PVA to
Wisconsin. A sfc cold front has slowly been moving across the
state today and is over central Wisconsin. More widespread lift
will produce scattered to isolated showers/storms across
southern Wisconsin this afternoon through tonight. The
environment is unstable through the column with sfc temps in the
80s to low 90s and dewpoints in the upper 60s to low 70s. South
to southeast winds have increase out ahead of the approaching
cold front. From ACARS and forecast soundings there is not much
shear outside of the 0-1 km layer currently or for tonight. 0-3
km shear is at its best across our northwest around 25 to 30
knots, but 20-25 kts is optimistic for the rest of southern
Wisconsin. So not a great environment for organized convection
through tonight.

The cold front will continue to advance east and CAMs continue
to show some weakening of the line as it hits eastern Wisconsin.
Forecast soundings show a fairly moist column throughout,
especially as the front begins to move in, but a few models do
try to bring in some CIN later this evening. Which is likely
what the most conservative models are latching onto. Not sure
where the middle level warm air or midlevel dryness is coming
from for these models to run away with. Low, mid and upper level
water vapor satellite shows moisture throughout the column and
doesn`t show any wing of dry air. Regardless kept rain chances
up as the front moves through around 60-80%. The highest rain
chances will be along the front and we are primed for rain. This
scattered to isolated nature from the CAMs will be something to
keep an eye on as we watch the segment of the line coming out of
IA through the afternoon. With the little shear and line
parallel winds, heavy rain and lightning are the major concerns
with any storms through tonight. Can`t rule out some brief gusty
winds, but the better chances for stronger winds will north and
west of Madison where there is better shear. Flooding concerns will
largely be limited to urban and small stream type of effects
where urban/city environments will struggle to take rain away
effectively and rises in small rivers and creaks are probable.

Given the slow moving nature of the front, isolated showers and
storms will be slow to make it to the far east and southeast.The chances
for any stronger storms or brief gusty winds will drop off
quickly after sunset as we look diurnal heating, but heavy
downpours will continue to be likely. Rain will be possible
through tonight and linger into tomorrow morning/early afternoon
for those eastern counties. As the frontal boundary lingers,
rain chances will remain, but will be low. Cooler and drier air
will move in behind the front keeping highs in the upper 70s to
low 80s. Dry weather is expected Sunday evening through Monday
night.

Patterson

&&

.LONG TERM...
Issued 307 PM CDT Sat Jul 5 2025

Monday through Saturday:

Cooler more near normal temperatures are expected through the
week with high in the upper 70s to mid 80s. High pressure will
move through the northern Great Lakes Region and Ontario Canada
Monday bringing dry weather and light winds.

Heading into Tuesday the high pressure will break down over the
Great Lakes Region and continue east. High pressure will build
back into the northern plains and the upper level steering flow
remains a bit zonal during this transition period. Multiple
little waves try to move through the upper level steering flow.
A few shortwaves will run over the ridge building in the west.
There is uncertainty in timing and placement of these
shortwaves, but guidance is maintaining consistency on a chance
of rain Tuesday afternoon into Tuesday night with POPs of 30 to
40%. Winds will return to southern Tuesday and humidity will
start to return so there is come decent confidence that with
enough lift we could see some scattered showers. The next chance
guidance highlights a better chance for rain will be Friday
night (40-50%). For friday guidance is latching onto a stronger
shortwave trough with an associated low pressure system, that is
expected to advect out of the Plains. Will have to keep an eye
on both chances for rain, but overall a more quiet forecast when
compared to previous weeks.

Patterson

&&

.AVIATION...
Issued 1005 PM CDT Sat Jul 5 2025

Decaying line of showers continue to move into southern WI
bringing scattered light to moderate rainfall. Will see some
pockets of lower ceilings with this activity, but otherwise VFR
conditions prevail. Models continue to try and build in lower
MVFR ceiling overnight into Sunday morning, but satellite
trends upstream continue to favor more scattered coverage of
these lower ceilings. Thus will continue to mention lower
ceilings, but will more than likely scatter out quicker than
the models prog. Otherwise, southwesterly winds continue
overnight before turning more west-northerly then northerly
Sunday morning into the afternoon as a weak cold front gradually
slides across the area. Cannot rule out a few showers and storms
to develop Sunday later morning early afternoon along the front
in southeast WI before pushing out, but potentially remains
low.


Wagner

&&

.MARINE...
Issued 307 PM CDT Sat Jul 5 2025

As a low pressure system advances east into the Upper Peninsula
of Michigan, breezy south to southeast winds have developed
across Lake Michigan with gusts of 20 to 25 kts possible. These
gusty winds have caused waves to build in the nearshore bringing
a moderate beach hazard to Sheboygan beaches and a Small Craft
Advisory for nearshore waters.

The low pressure system will continue east and drag a cold front
across the lake this evening through Sunday afternoon. Showers
and thunderstorms are expected along the front as it moves
through. The front is very slow moving so rain chances will
linger along the eastern coast into Sunday afternoon. Winds will
shift to the north to northwest behind the front with northerly
winds across the entire lake expected by Sunday afternoon.
North winds will remain over the lake through Monday evening.
High pressure will then build in over the lake bringing light
and variable winds through mid week.

Patterson

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Beach Hazards Statement...WIZ066-WIZ071-WIZ072...4 PM Sunday
     to 7 AM Monday.

LM...Small Craft Advisory...LMZ644-LMZ645-LMZ646...4 PM Sunday to 7
     AM Monday.

&&

$$

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