NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 221157
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
657 AM CDT Mon Jun 22 2026

.KEY MESSAGES...

- A High Swim Risk is in effect for Lake Michigan beaches in
  Racine and Kenosha counties this afternoon and evening, with a
  Moderate Risk for Milwaukee county. Keep out of the water and
  away from dangerous areas like piers and breakwalls!

- Chances for thunderstorms late Tuesday night through Wednesday
  evening.

- Below normal temps continue.

&&

.UPDATE...
Issued 700 AM CDT Mon Jun 22 2026

Powerful sunshine will continue to rapidly erode the existing
river valley and low-lying area fog early this morning.
Afterwards, should have mostly-clear skies through much of
today.

Departing low pressure is expected to produce some breezy north
to northeast winds over the southern half of Lake Michigan
today, which would allow waves to build to the 3 to 5 ft mark
for Racine and Kenosha county beaches this afternoon and
evening. Hence, a High Swim Risk is in effect. Northerly exposed
beaches will be at the greatest risk, particularly those along
and just north of Wind Point in Racine county.

Sheppard

&&

.SHORT TERM...
Issued 1055 PM CDT Sun Jun 21 2026

Today and Tonight:

A low pressure system in northeastern MO/central IL will
continue to move east toward the Mid Atlantic coast tonight. The
stratiform rain shield across the southern Great Lakes region
will continue to gradually shift east with the low bringing an
end to our rain tonight. Rain is already starting to end from
west to east yet tonight. Majority of the rain is expected to
end with in the next couple of hours. Some isolate light rain
could linger on the back side in the early morning hours, but by
and large all the rain will end prior to sunrise Monday. As this
low pressure system exits high pressure will be building in from
the Northern Plains. Skies will gradually begin to clear as the
stable air builds in and winds will become light. Lake shore
areas are expected to have the strongest winds of the day coming
off of lake Michigan which will keep temperatures cooler in the
low to mid 60s. Inland areas will be a bit warmer around the mid
70s. Scattered cumulus clouds are expected Monday afternoon
well inland from the lake. Dry conditions are expected to remain
through Monday night.

Patterson

&&

.LONG TERM...
Issued 1055 PM CDT Sun Jun 21 2026

Tuesday through Saturday:

An upper level trough will be descending down from southern Alberta
through the northern Plain and into the northern Great Lakes Region
late Tuesday. The sfc low will follow a very similar path and
is expected to cross through northern Wisconsin Wednesday. POPs
are expected to increase across the region from the northwest to
the southeast as this sfc low moves in. Instability should rise
across the state as a warm front moves through. This will bring
not only rain chances but also thunderstorms. The question
becomes how much instability and shear for any stronger to
severe storms. From some forecast soundings there looks to be
narrow CAPE and shear around 30 kts or more. So there is a
chance for storms, but each sounding that has both of these
features has a cap to contend with as well. So its looking like
this could be another conditional strong to severe storms
scenario as of now. This is still a couple of days out so things
could change, but a time period worth keeping an eye on.

For Thursday and Friday, there is some discrepancies around
500mb among guidance. Some build in ridging aloft faster than
others. High pressure is expected to move into the Great Lakes
Region briefly but timing and whether or not there could be some
lingering PVA aloft is still in question. The PVA aloft with
high pressure near the sfc has some low chance POPs (10-30%)
mixing in for both Thursday and Friday at times. Available
moisture and any forcing at the sfc will really be the catalyst
for any light rain during this time (a lake breeze could be just
enough forcing, convergence at the sfc, to get light rain).
Hard to tell if this will even be an issue if the upper level
ridge is in place aloft.

Next decent chance for rain looks to come Sunday into Monday as
a trough moves through the western CONUS toward the Great Lakes
Region. With there already being discrepancies in the 500mb
flow prior to this, models are just continuing to diverge from
each other further. Granted timing and strength seem to be the
biggest problems so POPs are still hitting a peak of 40-60%
Monday.

Patterson

&&

.AVIATION...
Issued 700 AM CDT Mon Jun 22 2026

River valley and low-lying area fog will continue to rapidly
burn off early this morning, leaving VFR and dry weather today
through the daytime hours of Tuesday. Some FEW/SCT diurnal
cumulus clouds will be possible today at around 5,000 ft. There
will be chances for fog to redevelop in these same susceptible
areas (WI River Valley and other low- lying marshy areas) late
Tonight into early Tuesday morning, particularly west of
Madison. Leaving that out of the TAFs for now due to low
confidence.

A light north to northeast breeze expected today, a few gusts
upwards of 20 KT possible for terminals along the Lake MI
shoreline this afternoon. Light and variable winds tonight into
Tuesday, with a localized easterly lake-breeze along the Lake
MI shoreline Tuesday afternoon.

Sheppard

&&

.MARINE...
Issued 1055 PM CDT Sun Jun 21 2026

Low pressure around 29.7 inches will track eastward from
northeastern Missouri to Ohio by Monday. Light easterly winds will
persist across much of the lake with breezy northeast winds across
the southern third tonight through Monday. As the low departs
and high pressure moves in the pressure gradient will tighten
just enough to build waves across the southern Wisconsin
nearshore. Waves are expected to be around 4 feet at time
Monday afternoon. A Small Craft Advisory is in effect for the
elevated waves for areas south of Lighter northerly winds are
expected late Monday evening into Tuesday as high pressure
around 30.1 inches builds into the region. Winds will become
light and variable Tuesday night as the high pressure tracks
overhead. By Wednesday, the high pressure will exit to the
southeast and low pressure around 29.8 inches moves from the
northern Plains into northern Wisconsin. As the low approaches
breezy south to southeast winds will develop across the lake.

Patterson

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Beach Hazards Statement...WIZ071-WIZ072...1 PM Monday to 9 PM
     Monday.

LM...Small Craft Advisory...LMZ645-LMZ646...1 PM Monday to 9 PM
     Monday.

&&

$$

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