NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 271144
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
644 AM CDT Wed May 27 2026

.KEY MESSAGES...

- A backdoor cold front will pass from mid afternoon into the
  early evening with 20-40 percent chances for showers and
  storms.

- A High Swim Risk and Beach Hazard Statement is in effect
  tonight into early Thursday afternoon due to dangerous
  currents from onshore winds and high waves.

- A Small Craft Advisory is in effect tonight into early
  Thursday afternoon due to persistent northeast winds and high
  waves.


&&

.UPDATE...
Issued 643 AM CDT Wed May 27 2026

A period of mid level clouds will continue this morning with the
passage of a shortwave trough, then giving way to more sunshine
and temps warming well into the 80s well away from Lake MI. For
later today, a west to east upper trough axis over Ontario will
track sewd into the nrn Great Lakes, then to the lower Great
Lakes tnt. Surface ridging will build into the nrn Great Lakes
behind this feature with the high settling over Lake Superior by
12Z Thu. The surface ridging will drive a backdoor cold front
across srn WI and adjacent Lake MI from mid afternoon into the
early evening. MLCAPE around 1000 J/KG is expected with little
to no capping but also weak surface convergence. Isolated to
scattered showers and storms (20-40 percent) are forecast from
late afternoon into the early evening. The cold front and nely
winds will then overtake all of srn tnt with cooler temps
arriving.


Gehring

&&

.SHORT TERM...
Issued 105 AM CDT Wed May 27 2026

Today through Thursday night:

An outflow boundary with modest north winds behind it continues
to push south across southern portions of the area, and should
exit to the south over the next few hours. A few weakening
showers or storms may still clip far northern or northwestern
parts of the area overnight. Otherwise, some middle to high
clouds should continue to move through the area into Wednesday
morning.

In addition, the backdoor cold front will move southward across
Lake Michigan overnight into this morning, pushing southwest
across the area later in the day. There is some question if this
will push into and through the area earlier in the day, with
gusty northeast winds behind it bringing in much cooler
temperatures closer to the lake. There is some uncertainty with
high temperatures on Wednesday, especially in northern and
eastern parts of the area, if the front moves in sooner. For
now, kept middle 80s well inland but have 60s along the
shoreline and 70s in between.

The front will also serve as a potential focal point for
isolated to perhaps scattered showers and storms by late
afternoon on Wednesday, mainly over northern portions of the
area, where the main upward vertical motion with the backdoor
cold front approaches. Mean layer CAPE around 500 to 800 J/kg
with weak capping and deep layer bulk shear around 20 knots or
so may bring gusty winds and brief heavy rainfall with any
stronger storms. Some CAMs are showing some activity moving
southward into the area by early evening, with others keeping
this just to the west of the area. So, still some uncertainty
with where showers and storms may occur. Kept PoPs in the 20 to
30 percent range for the most part in northern parts of the area
later this afternoon into early evening.

A Beach Hazards Statement for a high swim risk is in effect
from Wednesday evening into early Thursday afternoon for the
Lake Michigan beaches for Sheboygan, Ozaukee, Milwaukee, Racine
and Kenosha Counties. Increasing north to northeast winds will
bring building waves of 3 to 6 feet during this period. Life
threatening waves and currents are expected. Stay out of the
water, and away from dangerous areas like piers and breakwalls.

High pressure will push southward into the region later tonight
into Thursday night. Brisk northeast winds tonight should bring
cooler temperatures into the area for later tonight into
Thursday, coolest near Lake Michigan. Lows tonight should drop
to the lower to middle 50s. Highs Thursday should be in the 60s
near the lake with middle to upper 70s well inland. Thursday
night should be the coolest night, with lows in the upper 40s to
around 50 degrees.

Wood

&&

.LONG TERM...
Issued 105 AM CDT Wed May 27 2026

Friday through Tuesday:

Synopsis: Upper level ridging will gradually pivot/realign from
an Upper Mississippi Valley - Canadian Prairies to an Upper
Mississippi Valley - Hudson Bay axis this weekend into early
next week, with large scale subsidence supporting mostly dry
conditions and above normal temperatures across southern
Wisconsin. Currently expecting the warmest day of the period to
be Friday, when west southwest winds will be advecting a very
mild air mass from the Great Plains into the region.

Temperatures will trend modestly cooler Saturday through
Tuesday, as low level winds shift out of the east northeast,
bringing a modestly cooler upstream air mass into the area.
Despite the modest cool down, temperatures are still expected to
remain above normal from the weekend into early next week.

Saturday through Sunday: Forecast remains dry through this
portion of the period, but will need to be monitoring for
possible backdoor cold frontal passages, given the change in
larger scale wind pattern to east northeasterly/off of Lake
Michigan. Lift along any such boundaries will be fighting an
uphill battle against larger scale subsidence beneath the upper
ridging, though some global ensemble members are hinting at
light QPF during each afternoon period. Will thus be watching
trends over coming forecasts and making PoP adjustments if
necessary.

Quigley

&&

.AVIATION...
Issued 643 AM CDT Wed May 27 2026

VFR conditions today into Thu morning. Isolated to scattered
showers and storms are forecast late this afternoon and evening.
Cigs of 5-6 kft are expected.

Gehring

&&

.MARINE...
Issued 105 AM CDT Wed May 27 2026

A backdoor cold front is expected to push southwestward
overnight into this morning across Lake Michigan, which will
bring a quick north northeast wind shift behind it. Gusts up to
30 knots are possible along and behind this front over the open
waters. Winds will remain north northeast through Thursday,
gradually weakening Thursday night as high pressure around 30.2
inches builds into the Great Lakes region.

A Small Craft Advisory is in effect Wednesday evening into early
Thursday afternoon for gusty north northeast winds behind the
front and building waves of 3 to 6 feet.

A brief period of west to southwest winds over northern parts
of the lake may occur Friday, with lighter winds to the south,
as the high move slowly southeast of the area. An additional
backdoor cold front later Friday night into Saturday morning
will allow for brisk north to northeast winds once again through
Saturday. Winds should then weaken and remain fairly light
through early next week, under high pressure around 30.1 inches.

Wood

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Beach Hazards Statement...WIZ052-WIZ060-WIZ066-WIZ071-
     WIZ072...7 PM Wednesday to 1 PM Thursday.

LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646...7 PM
     Wednesday to 1 PM Thursday.

&&

$$

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