NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 201124
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
624 AM CDT Wed May 20 2026

.KEY MESSAGES...

- A Beach Hazard Statement is in effect tonight into tomorrow
  morning for a High Swim Risk at beaches in Milwaukee, Racine,
  and Kenosha Counties.

- Dry, but cooler today through Thursday with highs in the 50s
  to lower 60s due to onshore flow off of Lake Michigan.

- Expect a gradual warming trend through the Memorial Day weekend.

- Rain chances return Friday afternoon and night (40-70%), with
  lower chances through the holiday weekend.

&&

.UPDATE...
Issued 621 AM CDT Wed May 20 2026

A Beach Hazard Statement has been issued for Milwaukee, Racine,
and Kenosha Counties starting this evening and running into
Thursday morning. Gusty northeast winds are expected to drive
high waves and dangerous currents with north sides of piers and
breakwaters being favored areas for dangerous waters. Swimming
is not advised while the Beach Hazard Statement is in effect.

CMiller

&&

.SHORT TERM...
Issued 1120 PM CDT Tue May 19 2026

Today through Thursday:

Clouds linger overnight into early Wednesday morning as the
backside of the upper-level shortwave trough swings across the
the Upper Midwest. This cloud cover will help insulate temps
from falling as low as they could, but still expecting lows in
the 40s overnight. If there is any breaks in the clouds before
sunrise, could not rule out a few inland location dipping into
the upper 30s.

Otherwise the midweek pattern will be dominated by high
pressure building into the Upper Great Lakes region through the
day Wednesday. While expecting dry weather to prevail, expecting
northeast to easterly flow off of Lake Michigan through
Thursday. Thus, temps will remain much cooler along the lake and
inland to along the Kettle Moraine. Mainly looking at highs in
the 50s to around 60F, with coolest temps closer to the lake.
Meanwhile west of the Kettle Moraine will be less influenced
from the onshore flow, but still looking at daytime temps in the
lower 60s. Thursday is actually looking slightly cooler further
inland giving the easterly as compared to the northeasterly
winds today (Wednesday). However models continue to pick up on a
lake breeze developing later in the day due to the stronger
temp gradient paired with enhancement of the building high
pressure to the north. Thus this could push the cooler temps
inland faster in the afternoon than the current forecast, but
expect temps to fall pretty quick behind this lake breeze/front
later in the afternoon/evening dipping into the lower 50s and
upper 40s with overnight lows for Wednesday night in the lower
40s. Thursday night lows will be fairly similar in the 40s with
prevailing east winds as well.

Wagner

&&

.LONG TERM...
Issued 1120 PM CDT Tue May 19 2026

Friday through Tuesday:

An upper level trough will descend down from western Canada
into the northern plain then pivot northeast toward James Bay
for the weekend. As this upper level low pivots through
Minnesota Friday, a short wave will begin to pull up from the
desert southwest late Saturday into Sunday. Weak WAA will be in
place through the weekend so combined with the lift there will
be chances for rain Friday through Sunday. Friday by far looks
like the best time for rain with POPs around 60-80% Friday
night. POPs are trending later in the day which seems to be a
combination of dry air in the low level that will delay onset
and guidance overall trending a bit later in the day. If this
trend continues I could see the onset of rain and maybe a few
storms trending a bit later yet.

For Saturday and Sunday the lift from the shortwave will be a
bit weaker. Given this and the differences in timing and
location across models, POPs are hovering around 15-25%. WAA
will cause temperatures to climb both days with highs in the 60s
Saturday and mid 60s to upper 70s Sunday. So the instability
should be there and moisture, it will just depend on where and
when this larger scale lift moves through. Regardless this
should be less organized and more scattered than Friday.
Definitely NOT a wash out.

A quick area of weak high pressure looks to try to traverse the
Great Lakes Region for early next week. Guidance currently has
some low chance POPs for Monday and Tuesday, but unsure if this
will actually materialize. While the high pressure system is on
the weaker side the stationary front across the Ohio River
Valley should be far enough away to prevent any showers and
500mb clusters look to keep the ridging in place aloft. I'm sure
there are a few ensemble members trying to bring more moisture
and mid level support further north to justify the low POP
(10-20%). Either way, the better organization is to the south,
which means at worst it would be isolated to scattered showers
even if those few ensemble members hold out. Temperatures look
to continue to warm into mid week with a return to the 80s.

Patterson

&&

.AVIATION...
Issued 621 AM CDT Wed May 20 2026

VFR conditions are expected today. Winds will come around from
northerly to northeasterly today, with a better push of
northeasterly winds inland along the lakeshore from a lake
breeze late in the morning into the early afternoon.

CMiller

&&

.MARINE...
Issued 1120 PM CDT Tue May 19 2026

Lingering gusty winds this evening, but will gradually diminish
overnight as high pressure builds into the Upper Great Lakes
region Wednesday and Thursday. Still looking at gusty northeast
winds through midweek, especially over the southern half of the
lake and building waves along the western lakeshore. High
pressure continues to build to as it lifts northeastward across
Ontario and Quebec Friday through the weekend with easterly
winds persisting across Lake Michigan. Expecting winds to
increase during this timeframe as well with a broad low
pressure trough setting up over the Plains.

Wagner

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Beach Hazards Statement...WIZ066-WIZ071-WIZ072...7 PM
     Wednesday to 10 AM Thursday.

LM...Small Craft Advisory...LMZ645-LMZ646...7 PM Wednesday to 7 AM
     Thursday.

&&

$$

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