NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 240555
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1255 AM CDT Fri Jul 24 2026

.KEY MESSAGES...

- There is a Moderate Swim Risk this afternoon and evening for
  the Lake Michigan breaches in Sheboygan and Ozaukee Counties.
  Breaking waves and currents are expected. Stay away from
  dangerous areas like piers, breakwalls, and river outlets.

- Warmer and more humid conditions will bring chances for
  thunderstorms at times this weekend into next week.

- There is the potential for severe storms at times Sunday
  afternoon through Monday night.

&&

.SHORT TERM...
Issued 1255 AM CDT Fri Jul 24 2026

Today through Saturday night:

West northwest flow at 500 mb will linger into tonight, with
high pressure at the surface lingering to the southeast of the
area. The high will continue to bring dry conditions to the area
during this period.

Some broken stratocumulus clouds may linger into early this
morning, as more high clouds move eastward into the area. Some
partial clearing may occur in the morning, before more scattered
to broken diurnal stratocumulus clouds develop with daytime
heating. These should linger through the afternoon into early
evening.

Light winds will become south southwest later this morning into
this afternoon. Another gusty southeast lake breeze is expected
this afternoon near Lake Michigan.

Lows early this morning should drop into the middle 50s inland,
with upper 50s to lower 60s lakeside. Highs today should reach
the upper 70s to lower 80s, turning cooler near the lake in the
afternoon.

There is a Moderate Swim Risk this afternoon and evening for
the Lake Michigan beaches in Sheboygan and Ozaukee Counties.
Gusty southeast winds should bring waves of 3 to 4 feet in these
areas during this period. At this time, not expecting a High
Swim Risk, but will monitor trends in later forecasts.

Modest warm air advection develops over the area Saturday into
Saturday night, with modest southwest winds developing at the
surface. This should bring warmer and more humid conditions into
the area, with highs into the middle 80s over most of the area
Saturday. Dew points will rise well into the 60s as well.

The warm air advection/possible warm frontal passage may try to
help generate some shower or thunderstorm activity Saturday
into Saturday night, as the low level jet tries to point
eastward toward the area from the west. However, area forecast
soundings are quite capped even at 850 mb, so not very
optimistic about elevated convection developing over the area.

Perhaps something may develop to the west and slide southeast
and clip the area Saturday night, but this may be tough given
the capping in place. For now, left small chances (around 20
percent) in the western areas for later Saturday night into
Sunday morning.

Wood

&&

.LONG TERM...
Issued 1255 AM CDT Fri Jul 24 2026

Sunday through Thursday:

There are better chances for showers and thunderstorms at times
(30 to 40 percent) Sunday afternoon into Monday evening, as
weak warm air advection lingers with possible 500 mb vorticity
maxima shifting through the area at times. In addition, the low
level jet nose may develop rounds of convection over southern
Minnesota and northern Iowa and shift it southeastward into or
clipping parts of southern Wisconsin.

Sunday/Sunday night may be tougher to get storms to develop or
maintain themselves than Monday/Monday night, as the capping
will remain fairly strong per area forecast soundings. Again, it
may be more likely that something moves southeast into the
area, though it will be battling a more capped environment.

The capping on Monday afternoon and night is far lower, which
would help convection develop and maintain strength as it shifts
southeast through the area. Models are also hinting at a low
pressure system shifting southeast through the western Great
Lakes region either later Monday or Monday night, which may drag
a cold front through and help with upward vertical motion.

For the Sunday afternoon into Monday evening period, there will
be a lot of mean layer CAPE (over 3000 J/kg) with increasing
deep layer bulk shear (25 knots Sunday/Sunday night and 25 to 30
knots or more Monday/Monday night). So, severe storms are
possible if something can get going. The uncertainty lies with
timing and where storms may track, and if there will be several
rounds. Keep up with the forecast for this period.

In addition, highs should reach into the lower 90s Sunday and
Monday, with dew points into the lower to middle 70s. This may
bring heat index values to around or a little above 100 degrees,
so heat headlines may eventually be needed if this comes to
fruition. Warm and humid conditions are likely to linger through
next week per ensemble trends and the low temperature spreads
on the NBM.

There may be a lull in the active weather Tuesday into
Wednesday, as high pressure moves through in continued northwest
flow aloft. There may be more active weather again later in the
week, as more systems start to shift southeastward through the
region at times per ensemble member trends.

Wood

&&

.AVIATION...
Issued 1255 AM CDT Fri Jul 24 2026

High pressure lingers to the southeast of the area today into
tonight. The high will continue to bring dry conditions to the
area during this period.

Some broken stratocumulus clouds around 7000 feet AGL may
linger into early this morning, as more high clouds move
eastward into the area. Some partial clearing may occur in the
morning, before more scattered to broken diurnal stratocumulus
clouds with ceilings around 6000 feet AGL develop with daytime
heating. These should linger through the afternoon into early
evening.

Light winds will become south southwest later this morning into
this afternoon. Another gusty southeast lake breeze is expected
this afternoon for terminals near Lake Michigan.

Wood

&&

.MARINE...
Issued 1255 AM CDT Fri Jul 24 2026

South winds will increase across the lake today, as high
pressure moves further to the east. Low pressure around 29.5
inches will move quickly east from the Canadian Great Plains
toward Quebec today through Saturday, maintaining gusty south to
southwest winds. Southerly gusts up to 30 knots are expected
over the north half of the lake.

A Small Craft Advisory is in effect for the nearshore waters
north of Port Washington for later this afternoon into this
evening, for gusty south to southeast winds and building waves.

The low pressure system will pull a cold front into the western
Great Lakes on Saturday, with the boundary slowly advancing
southeast across the region Saturday night. This will result in
increasing thunderstorm chances across the northern two thirds
of the lake. The front then becomes stationary through the
middle of next week, with switches between northerly and
southerly winds possible at times. Additional rounds of storms
are possible, and some may become severe.

Wood

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Small Craft Advisory...LMZ643...4 PM Friday to 10 PM Friday.

&&

$$

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