NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 240000 AAA
AFDMKX

Area Forecast Discussion...UPDATED
National Weather Service Milwaukee/Sullivan WI
700 PM CDT Thu Jul 23 2026

.KEY MESSAGES...

- There is a Moderate Swim Risk Friday 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 Sunday through
  Monday.

&&

.UPDATE...
Issued 700 PM CDT Thu Jul 23 2026

West northwest flow at 500 mb will linger tonight into Friday
night, 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.

Mainly broken stratocumulus clouds should linger for a time this
evening and may linger overnight, though these may slowly
dissipate with more high clouds moving eastward into the area
overnight into Friday morning. 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 Friday evening.

The gusty southeast lake breeze should linger until early this
evening, before weakening and becoming south by middle evening.
Light south winds are expected elsewhere tonight, with light
south southwest winds on Friday. Another gusty southeast lake
breeze is expected Friday afternoon near Lake Michigan.

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

There is a Moderate Swim Risk Friday 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.

Wood

&&

.SHORT TERM...
Issued 211 PM CDT Thu Jul 23 2026

Tonight through Saturday:

Light and variable winds with mostly clear skies are expected
tonight as high pressure gradually drifts across Lower Michigan.
Look for steadier southwest winds to develop Friday. This will
keep the lake breeze closer to the shoreline for the afternoon.
Afternoon highs will be a little warmer than today, closer to
80.

Breezy south-southeast winds 15 to 25 kt will build waves up to
2 to 4 feet toward areas north of Port Washington later Friday
afternoon into Friday evening. A Moderate Swim Risk is expected
for Sheboygan and Ozaukee counties.

The heat will begin to move in Saturday with highs in the mid to
upper 80s and dewpoints climbing toward 70. A weak surface
trough will approach from the Northern Plains Friday night and
stall somewhere in the vicinity of central WI. With the weak
forcing models have difficulty pinpointing it this far out.
There could be a few showers that develop along this frontal
boundary Saturday afternoon or evening, but there is not much
confidence here so the forecast is dry for now.

Cronce

&&

.LONG TERM...
Issued 211 PM CDT Thu Jul 23 2026

Sunday through Thursday:

The stalled frontal boundary will be the focus for shower and
thunderstorm development on Sunday. Exactly where the boundary
will be is still in question, but somewhere in Wisconsin. We are
leaning toward central at this time. Initiation of storms could
wait for the low level jet to develop in the evening, but it
could also go earlier in the afternoon with the convective
temperature, subtle mid level shortwave trough, and 850mb warm
air advection.

Models are showing high CAPE (over 3000 j/kg) and somewhat of a
straighter hodograph for southern WI with bulk shear of around
40 kt. One possibility is that storms initiate in central WI and
then dive southeast through southern WI with wind a decent
threat. That is only one possibility, because if the storms
initiate in southern WI if the boundary is this far south and we
can tap into better directional shear, then all hazards will be
a concern. SPC introduced a 15% risk for severe storms Sunday
AND Monday for southern WI.

Wherever the storms lay out a boundary Sunday night could end up
being the focus for additional storms Monday. In addition,
another shortwave trough is expected to roll across Lake
Superior (or northern WI) Monday afternoon. This could also
trigger storms. As long as the environment has time to recover
between Sun evening and Mon afternoon, there will be a severe
risk once again.

Generally speaking, there will be a warm and humid ridge sitting
over the center of the country through most of next week.
Wisconsin will be on the northern periphery of this ridge, thus
warm and humid in southern WI and cooler/less humid in northern
WI. We will be in the vicinity of the "ridge riders" where storm
complexes can develop each evening on the nose of the low level
jet. There is not guarantee that we will see storms every day,
but the risk is certainly there for much of the week.

Cronce

&&

.AVIATION...
Issued 700 PM CDT Thu Jul 23 2026

High pressure will linger tonight into Friday night to the
southeast of the area, bringing dry conditions.

Mainly broken stratocumulus clouds with ceilings around 6000 to
7000 feet AGL should linger for a time this evening and may
linger overnight. However, these may slowly dissipate with more
high clouds moving eastward into the area overnight into Friday
morning.

Some partial clearing may occur Friday morning, before more
scattered to broken diurnal stratocumulus clouds with ceilings
around 5000 to 6000 feet AGL develop with daytime heating. These
should linger through the afternoon into early Friday evening.

The gusty southeast lake breeze for terminals near Lake Michigan
should linger until early this evening, before weakening and
becoming south by middle evening. Light south winds are expected
elsewhere tonight, with light south southwest winds on Friday.
Another gusty southeast lake breeze is expected Friday afternoon
for terminals near Lake Michigan.

Wood

&&

.MARINE...
Issued 211 PM CDT Thu Jul 23 2026

Breezy south-southeast winds 15 to 25 kt will build waves up to
2 to 4 feet toward areas north of Port Washington later Friday
afternoon into Friday evening. A Small Craft Advisory is in
effect.

Light and variable winds will continue through tonight as high
pressure around 30.1 inches drifts across lower Michigan.
Southerly winds develop Friday as the high moves 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 south to southwest winds
over Lake Michigan. Southerly gusts up to 30 kt are expected
over the north half.

The associated frontal boundary will slowly advance southward
across the waters Saturday night, resulting in thunderstorm
chances for the north half of Lake Michigan. The front is
expected to sit across Lake Michigan through the middle of next
week, so there will be switches between northerly and southerly
winds at times. This front will be the focus for several rounds
of thunderstorms, possibly severe Sunday and Monday.

Cronce

&&

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

&&

$$

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