NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 251049
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
549 AM CDT Mon May 25 2026

.KEY MESSAGES...

- A Dense Fog Advisory is in effect for the entire open lake of
  Lake MI until 10 AM CDT today.

- A Moderate Swim Risk is forecast this afternoon and evening
  for Lake MI beaches in Sheboygan and Ozaukee Counties.

- A backdoor cold front Wednesday will bring gusty northeast
  winds behind it near the lake and much cooler temperatures.
  This front will also bring chances for showers and storms
  (around 20 to 50 percent) Wednesday afternoon.

- Dry for later this week into the weekend with above normal
  temperatures.

&&

.UPDATE...
Issued 550 AM CDT Mon May 25 2026

The showers and isold thunderstorms over nrn IA and se MN should
continue to weaken as they move into dry air over sw WI. The
warm advection pattern and weak shortwave trough passage may
still support isold showers this morning into the early
afternoon via mid level moisture and instability. Despite the
early cloud cover, improved sky conditions later in the day
should still boost temps into the lower to middle 80s away from
Lake MI. Light swly winds will then persist tnt-Tue with very
warm temps of 85-90F for Tue afternoon.

Modest sly winds near the lake and building waves will support
Moderate Swim Risk conditions for Ozaukee and Sheboygan beaches.

Gehring

&&

.SHORT TERM...
Issued 114 AM CDT Mon May 25 2026

Today through Tuesday:

Patchy dense fog may occur close to the Lake Michigan shore
overnight into the middle morning hours, if it moves onshore
from the lake. See Marine section for more information on the
Dense Fog Advisory over Lake Michigan.

There are mainly small chances (around 20 percent) for weakening
showers to clip far western and northwestern portions of the
area this morning. The main area of warm air advection and the
low level jet axis should remain far enough to the west and
northwest to keep most of this activity there. CAMs seem to
generally support this, but some do have some weakening showers
moving into the far western areas this morning.

Otherwise, middle level clouds will move through overnight into
today. There should be some diurnal cumulus clouds as well in
the afternoon hours. Light south winds overnight should become
south to southwest today, with a southeast lake breeze for
areas near the lake in the afternoon. Highs should reach the
middle 80s Monday for most of the area, turning cooler near the
lake.

High pressure to the southeast of the region should keep the
area mostly dry for tonight into Tuesday. Southwest winds on
Tuesday will bring warm temperatures once again, with a
southeast lake breeze in the afternoon near the lake. Highs in
the upper 80s are anticipated over most of the area, perhaps
reaching 90 degrees in spots.

Wood

&&

.LONG TERM...
Issued 114 AM CDT Mon May 25 2026

Tuesday night through Sunday:

Showers and storms may develop near a stationary front in
northern Wisconsin Tuesday evening and overnight, which may try
to sag southward toward the area. For now, kept 20 percent
chances for showers and storms in far northern parts of the
area. Not confident that this activity may reach these areas
before it dissipates.

A backdoor cold front should move southward across Lake Michigan
Wednesday morning, with the front shifting southwest into the
area during the day. This feature should bring chances (20 to 50
percent) for showers and storms in the afternoon with peak
heating and mean layer CAPE of 500 to 800-plus J/kg. The deep
layer shear is weak, so would expect mainly pulse-type storms in
an uncapped environment.

In addition, gusty north to northeast winds behind the front
near the lake should bring dropping temperatures into the 60s
there. This may also occur inland, though it may be tougher for
the front to push this cooler air into the area and battle
daytime heating. So, some uncertainty with highs inland exist,
especially in northern parts of the area.

500 mb cluster analysis continues to show an omega block-like
pattern developing over the north central part of the country,
with a ridge axis building over the region into next weekend.
This should allow for a trough to the east and well to the west,
which may allow for surface high pressure to remain to the north
and northeast of the area per ensemble means. Thus, it appears
to be a fairly dry period. Temperatures should remain above
seasonal normal values per ensemble trends.

Wood

&&

.AVIATION...
Issued 550 AM CDT Mon May 25 2026

Areas of MVFR BR through 14Z this morning over far ern WI.
Otherwise VFR conditions today into Tue AM. Mid level clouds and
light showers expected this morning into the early afternoon.

Gehring

&&

.MARINE...
Issued 550 AM CDT Mon May 25 2026

High pressure around 30.2 inches will move from lower Michigan to
the lower Great Lakes today. The moist southerly flow over the
cold waters of Lake Michigan will maintain dense fog over much of
the lake this morning. A Dense Fog Advisory is in effect. Areas of
fog, possibly dense, may continue into the afternoon.

Modest southerly winds will continue tonight into Tuesday, while
high pressure around 30.3 inches is expected to build toward
eastern Hudson Bay Tuesday into Wednesday. This will eventually
move a cold front southward over Lake Michigan for Tuesday night
and Wednesday. Winds will shift northeasterly after the frontal
passage.

Gehring

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Dense Fog Advisory...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-
     LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-
     LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 until 10 AM
     Monday.

&&

$$

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