NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 231047
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
547 AM CDT Thu Jul 23 2026

.KEY MESSAGES...

- Dry and pleasant conditions are expected into Friday. Warmer
  and more humid conditions are expected this weekend into next
  week.

- Chances for showers and thunderstorms (20 to 30 percent)
  return to the area at times Sunday night into early next week.

&&

.UPDATE...
Issued 517 AM CDT Thu Jul 23 2026

Light and variable winds with mostly sunny to partly cloudy
skies are expected again today. The partly cloudy skies will
come with the development of diurnal cumulus clouds late
morning. The diurnal cumulus clouds are expected to remain
through the evening. The early morning valley/river fog for
areas west of Madison is visible on satellite. This is patchy
fog that will stay contained to low lying areas. Any fog that
has developed will burn off shortly after sunrise. No major
changes to the forecast.

Patterson

&&

.SHORT TERM...
Issued 1238 AM CDT Wed Jul 22 2026

Today through Friday:

Northwest flow at 500 mb is expected to linger across the region
during this period. High pressure will move southeast across
the area into this morning, before shifting to the southeast in
the afternoon and tonight. Dry and pleasant conditions are
expected. Light and variable to calm winds overnight may lead to
some fog in the Wisconsin River Valley and other low lying
areas.

Another round of scattered to mainly broken stratocumulus
clouds are anticipated this afternoon, with more middle level
clouds moving eastward into the area tonight. A southeast lake
breeze is expected again this afternoon near Lake Michigan,
with light southwest winds inland.

After a cool start this morning, highs today will be mainly in
the upper 70s, turning a little cooler near the lake in the
afternoon. Lows in the middle to upper 50s are expected
tonight, with light winds.

The high will move further southeast of the region on Friday,
with more southerly winds developing across the area. There
should still be a southeast lake breeze for areas near Lake
Michigan in the afternoon, along with another round of diurnal
scattered cumulus clouds. Highs should be in the upper 70s to
lower 80s, turning a little cooler near the lake in the
afternoon.

There may be a moderate swim risk that develops later Friday
afternoon into Friday evening for Lake Michigan beaches in
Sheboygan and Ozaukee Counties. South southeast winds will
increase during this time, allowing waves to build to 3 to 4
feet.

Wood

&&

.LONG TERM...
Issued 1238 AM CDT Wed Jul 22 2026

Friday night through Wednesday:

500 mb cluster analysis continues to show an anomalous ridge
axis developing over the northern Plains into south central
Canada this weekend into early next week. This should keep the
area within northwest flow at 500 mb during this period. This
may allow for periodic chances for showers and thunderstorms
later this weekend into early next week, with a few shortwave
troughs possibly shifting through.

Warm air advection in the low levels with south to southwest
winds developing this weekend should bring warm and humid
conditions back into the region. There are small chances (around
20 percent or less) for a few showers or storms to develop
Saturday night within the warm air advection regime, though it
may be too capped per forecast soundings for anything to
develop. Kept forecast dry for now.

A warm front may move through the region Sunday or Sunday
night, which may bring a more organized period of showers and
storms. This potential may linger into early next week, until
the low pressure system shifts southeast by Tuesday. These rain
chances should be periodic and not continuous. Given the
instability and shear within northwest flow aloft, there may be
some strong to severe storm potential Sunday into Monday night.
Details will hopefully become more clear in the coming days.
Ensembles continue to keep the warm and humid conditions going
into next week, with rather small temperature spreads each day.

Wood

&&

.AVIATION...
Issued 517 AM CDT Thu Jul 23 2026

Predominately VFR conditions are expected through the period.
The small pockets of MVFR conditions will be in low lying areas
and river valleys west of Madison for fog. The patchy fog that
has developed this morning could drop visibilites for near by
terminals (ie: LNR) to around 3-5 SM. The patchy fog should burn
off/diminish a hr or two after sunrise. Diurnal cumulus is
expected to develop again late this morning around 4-6 kft and
persist through the evening. Light and variable winds are
expected for much of the day and through tonight. A lake breeze
is expected to develop this afternoon and move inland which will
temporarily bring easterly winds as it moves through before
returning to light and variable. The lake breeze is not expected
to make it very far inland, which will leave western terminals
like MSN and JVL untouched. Light south to southwest winds are
expected by Friday.

Patterson

&&

.MARINE...
Issued 1238 AM CDT Wed Jul 22 2026

Light and variable winds are expected overnight into Thursday,
as high pressure around 30.1 inches crosses Wisconsin and
southern Lake Michigan. Look for southerly winds to develop by
Friday, as the high move into the northeastern United States. A
29.5 inch low pressure system will move quickly from the
Canadian Great Plains toward Quebec Friday through Saturday,
maintaining increasing south to southwest winds over Lake
Michigan.

Some showers and storms may occur Saturday night over northern
portions of the lake, with warmer and more moist air moving into
the region. Another low pressure system around 29.5 inches may
moves southeast through the region later this weekend into early
next week, bringing periodic chances for showers and
thunderstorms.

Waves may build to 3 to 4 feet toward areas north of Port
Washington later Friday afternoon into Friday evening, as
increasing south southeast winds occur.

Wood

&&

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

$$

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