065
FXUS63 KMKX 210654
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
154 AM CDT Thu Aug 21 2025

.KEY MESSAGES...

- Fog potential tonight, especially west of I-90.

- Next chance of rain/storms is late Friday into Saturday
  morning with a cold front.

- Much cooler, less humid, and breezy from later Saturday into
  early next week.

&&

.SHORT TERM...
Issued 200 AM CDT Thu Aug 21 2025

Today through Friday:

Very quiet these next few days for the most part. Outside of
some areas of fog this morning and again Friday morning which will
quickly dissipate after daybreak high pressure and upper level
ridging will dominate the next few days allowing for a beautiful
next few days with plenty of sun and highs in the upper 70s.
However a period of clouds in central WI and migrating into
part of southern WI is expected to perhaps limit sunshine to
some degree at least for the morning hours today.

Generally the high will migrate south today and then more
southeast into Friday as it gradually exits. Clouds will start
to push in later Friday but dry air should keep at least some
sun well into the afternoon for most of the CWA. By the early
evening clouds will start to become a bit more widespread as the
Shortwave and associated front approaches from the north.

Kuroski

&&

.LONG TERM...
Issued 200 AM CDT Thu Aug 21 2025

Friday night through Wednesday:

An initial wave of showers and thunderstorms will progress
southeastward across Wisconsin Friday night as low pressure
develops across northwestern Ontario. Limited instability (MUCAPE
1000 to 1500 J/kg, with capping in place) and PWATs on the lower
side (between 1.25 and 1.5 inch) will keep the severe potential
minimal. The main cold front lags behind this wave and makes its
appearance into Saturday, bringing additional showers and
thunderstorms Saturday morning into Saturday afternoon before
ending. Still not anticipating severe weather with this front,
primarily expecting showers with isolated thunder embedded within
it. After the front moves through, wrap around showers remain
possible as the low occludes across northeastern Ontario and
continues to wrap waves of moisture around the back side of it.

Breezy northwest flow then develops Saturday afternoon and
continues through at least midweek next week. This will usher in a
period of cooler than normal temperatures, with highs in the upper
60s to low 70s and lows in the upper 40s to low 50s. Additional
shortwaves rotating through the upper level low may produce
additional rounds of showers Sunday and Monday, although
confidence is low at this time (15-25 percent chance on Sunday,
~15 percent chance on Monday as moisture flow weakens). Low
pressure exits to the east into Wednesday, with high pressure
propagating eastward from the Plains and bringing a return to
temperatures in the 70s.

MH

&&

.AVIATION...
Issued 200 AM CDT Thu Aug 21 2025

Some patchy fog is expected early this morning through the early
daylight hours, primarily further west. Models are uncertain on
how widespread/dense it will be but generally at least some
patchy MVFR VSBYs are expected with some areas falling to
IFR/LIFR at times with as low as 1 SM VSBYs possible. In
addition there remains some lingering low CIGS in the region,
especially closer to the lake where moisture off the lake seems
to be helping develop at least some SCT MVFR CIGS. However it is
expected that as northeast winds over the lake weaken over the
next few hours, with limited moisture regionally, that these
lower CIGS will dissipate. Still some mild uncertainty on that
but we will keep things updated to reflect the latest thinking.

Into the morning any CIGS and fog are expected to dissipate with
high pressure and mostly sunny skies expected the rest of the
day. Overnight into Friday we could see another period of patchy fog
and perhaps a few spots with lower CIGS, primarily further west
again.

Kuroski

&&

.MARINE...
Issued 200 AM CDT Thu Aug 21 2025

High pressure of 30.1 inches will slowly sink southeastward from
northern WI to southern WI through today, lingering into
Friday but gradually weakening and shifting southeast. Expect
fog to develop across the northern third of the lake as light
and variable winds prevail under high pressure. Patchy dense fog
is possible. Light and more variable winds are expected across
the lake into the day today as high pressure settles into the
region and decreases winds across the entirety of the lake.

Winds turn southerly to southwesterly Friday afternoon ahead of a
strong cold front, which will pass across the lake on Saturday.
Expect scattered showers and thunderstorms along this front. Gusty
west to northwest winds are expected from late Saturday through
Monday behind this cold front as low pressure of 29.5 inches
occludes over northern Ontario.

Kuroski

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Beach Hazards Statement...WIZ066-WIZ071-WIZ072 until 4 AM
     Thursday.

LM...Small Craft Advisory...LMZ644-LMZ645-LMZ646 until 4 AM
     Thursday.

&&

$$

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