160
FXUS63 KMKX 170736
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
236 AM CDT Thu Jul 17 2025

.KEY MESSAGES...

- High swim risk is expected through tonight for the Lake
  Michigan beaches from Sheboygan to Kenosha County.

- Drier, less humid, and cooler with temps 5-10F below normal
  are expected today and Friday.

- Unsettled weather returns for later Friday night into the
  weekend, with 30-50 percent chances for showers and
  thunderstorms at times.

&&

.SHORT TERM...
Issued 233 AM CDT Thu Jul 17 2025

Today through Friday:

Some patchy lingering drizzle on the backside of the the upper-
level trough will accompany the lower ceilings early this
morning. Will see these lower ceilings lift and push out through
daybreak as subsidence and drier airmass from the high pressure
over the Northern Plains creeps eastward across MN and
eventually over WI by the late afternoon/early evening.
Expecting quieter weather today with the incoming high and
upper-level zonal flow. Main story is the below normal temps
with highs in the lower 70s and lows in the 50s which would be
5-10F below normal for this time of year (normal temps MKE-
H:82F / L:65F, MSN- H:82F / L:62F). Otherwise, the breezy
north/northeasterly flow over Lake Michigan will build waves of
greater than 3 feet resulting in high swim risk conditions
through the day between Sheboygan Co beaches down through
northern IL beaches. Use extreme caution if swimming along area
beaches, especially northerly exposed beaches, structures, and
breakwalls as these areas will be more prone to the development
of life- threatening currents.

Quiet and dry conditions will continue into Friday as zonal
upper- level flow remains in place over the Upper Midwest.
However, the surface high will works its way east overnight
tonight in Friday and will begin to see southerly flow begin to
advect in warm temps for Friday. High temps look to top off in
the mid to upper 70s and a few locations cracking 80F,
especially given the ample sunshine.

Wagner

&&

.LONG TERM...
Issued 233 AM CDT Thu Jul 17 2025

Friday night through Wednesday:

A wave of warm air advection is expected in association with a
sfc warm front and weak low level jet over Iowa Friday night.
Saturday, this wave is expected to lean over into southern
Wisconsin, with varying times of arrival, magnitude, and
progression through the models. The NAM and GFS favor a complex
of storms rolling through on Saturday riding the warm
advection, with the NAM largely pushing the wave through by 21Z,
while the GFS lingers precip into the late evening. ECMWF and
Canadian solutions are a wash, showing some vague chances for
precipitation, but a far less pronounced WAA wave. For now, the
NBM paints 40 to 60% PoPs over southern WI, with the best
chances before noon, and decreasing chances into the evening
hours. Trends will be monitored for better agreement with time.
Even with the disagreement, sfc dew points are expected to rise
amid the warm advection, and could be muggy again starting
Saturday.

Models then agree that following storm chances Saturday, a
small push of dry air and relative high pressure will build in
Saturday night through most of Sunday, keeping most of the day
dry. By Sunday night, some low precipitation chances may return
as a stationary/warm front sharpens over the Corn Belt and some
warm advection returns to the region. Humidity is expected to
build again, and Monday and Tuesday may feature some weakly
forced shower and storm chances (PoPs 20 to 35%) as this frontal
boundary lifts slowly northward. There are then indications
that there may be hot and humid conditions with heat indices
approaching 100 by the middle of next week.

CMiller

&&

.AVIATION...
Issued 233 AM CDT Thu Jul 17 2025

Lower stratus deck bringing MVFR and IFR ceilings along with
patchy drizzle will linger through the later morning hours.
Gusty northerly winds will continue through the morning as well.
However, ceilings are progged to improve to VFR at the earliest
late morning, but more likely through the early afternoon from
west to east. Winds will ease during this time as well as high
pressure skirts across MN and pushes over WI by this evening.
This will bring light and variable winds along with mostly clear
conditions tonight given the subsidence. VFR conditions and
light winds will persist into Friday before shower and storms
chances increase later friday night into the weekend.

Wagner

&&

.MARINE...
Issued 233 AM CDT Thu Jul 17 2025

Stronger northerly with gusts of 30 knots will continue across
the open waters through the morning as low pressure tracks
across lake Huron. Will see gusty winds and building waves of
greater than 4 feet in southern WI nearshore waters today as
well resulting in a Small Craft Advisory. Gusty winds will
gradually weaken through the afternoon and evening as high
pressure moves across MN and over WI. Lighter winds expected
Thursday night into Friday as the high moves over Lake Michigan
before sliding east Friday afternoon. Then a warm front will
lift north-northeastward up across Lake Michigan later Friday
and stall across the mid-lake. Winds across the southern half of
the open waters will be southerly with more east-northeast
winds across northern portions of the lake north of the stalled
front. Another broad, weak low pressure looks to work its way
across the mid-lake later Saturday brining a period of varying
winds and thunderstorms. Then another high pressure sets up
across the Upper Great Lakes for Sunday.

Wagner

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Beach Hazards Statement...WIZ052-WIZ060-WIZ066-WIZ071-WIZ072
     until 1 AM Friday.

LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 1 AM
     Friday.

&&

$$

Visit us at weather.gov/milwaukee

Follow us on Facebook, Twitter, and YouTube at:
www.facebook.com/NWSMilwaukee
www.twitter.com/NWSMilwaukee
www.youtube.com/NWSMilwaukee