872
FXUS63 KMKX 052007
AFDMKX

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

.KEY MESSAGES...

- Showers and thunderstorms are expected this afternoon through
  tonight. A few storms could produce gusty winds and locally
  heavy rainfall.

- Hot and muggy conditions continue with heat indices in the
  low to mid 90s.

- Small Craft Advisory remains in effect this afternoon in all nearshore
  zones.

- Periods of moderate swimming risk this afternoon at Sheboygan
  County beaches.

- Poor air quality expected near Lake Michigan today.

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


&&

.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 307 PM CDT Sat Jul 5 2025

VFR conditions will prevail under mostly clear skies through
mid afternoon. By late this afternoon, a low pressure system
will advect east out of Minnesota and bring a cold front across
the state. Multiple rounds of scattered to isolated rain and
thunderstorms are expected as this front moves through. The
front will be slow moving so rain chances will last into the
overnight hours. Far southeastern Wisconsin will see rain linger
into Sunday morning. Gusty south to southeast winds have
developed late this morning and will continue out ahead of the
front with gusts 25-30 MPH possible. Highlighted the highest
confidence for rain/storms in the TAFs. MVFR to IFR ceilings and
visibilites are expected as the rain and storms move through.
MVFR ceilings are likely to persist behind the passage of the
cold front tonight into early Sunday morning.

Patterson

&&

.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...None.
LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 8 PM
     Saturday.

&&

$$

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