NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 091042 AAA
AFDMKX

Area Forecast Discussion...UPDATED
National Weather Service Milwaukee/Sullivan WI
542 AM CDT Tue Jun 9 2026

.KEY MESSAGES...

- A few showers and isolated thunderstorms will continue today.

- Multiple rounds of storms are expected Wednesday and Thursday.
  Severe thunderstorms are likely at times.

- Hot and humid conditions expected Wednesday and Thursday, with
  some potential for Heat Advisory conditions on Wednesday if we
  get enough sunshine.

&&

.UPDATE...
Issued 542 AM CDT Tue Jun 9 2026

Areas of dense fog developed near the lakeshore of Sheboygan
county and has expanded inland early this morning. The fog was
apparent on lakeshore webcams, the webcams at Road America, and
the WI DOT webcams. The Sheboygan airport reported one quarter
mile visibility between 1 and 3 AM and now has an upward trend.
The Dense Fog Advisory is in effect for only Sheboygan county
until Noon, but it is likely we can cancel it early.

The storm potential is trending downward for today, but we can
still expect isolated showers with a few rumbles of thunder for
at least the morning hours.

Cronce

&&

.SHORT TERM...
Issued 1238 AM CDT Tue Jun 9 2026

The rest of tonight through Tuesday:

Weak low pressure will gradually lift northeast through the
forecast area tonight into Tuesday, with continued scattered
showers and a few rumbles of thunder at times. The shower
chances will wind down from southwest to northeast overnight
into Tuesday, with the chances mainly east of Madison by Tue
afternoon as the low begins to pull away from the area.

Mild temps are expected overnight tonight due to the moist
airmass and persistent clouds. Bumped Tue high temps down a
couple degrees from the previous forecast given the expected
lingering clouds tomorrow.

DDV

&&

.LONG TERM...
Issued 1238 AM CDT Tue Jun 9 2026

Tuesday night through Monday:

An area of moisture and warm air advection is expected to lift
into the forecast area Tue night into early Wed. This may kick
off a round of thunderstorms after midnight. Latest guidance is
showing plenty of instability hanging on overnight along with
modest 0-6 km shear around 30 knots. Additionally, mid-level
lapse rates are expected to be upwards of 8-9 C/km Tue night
into early Wed. If storms do develop overnight, confidence is
increasing for a severe threat, with hail being the primary
concern.

Storms should wind down by mid-morning Wednesday, with a break
in activity likely late morning into the afternoon. This should
be enough time for instability to build back up across southern
Wisconsin, with another round of storms possible by early
evening as a shortwave moves into the area. This second round of
storms may develop just to the west of the forecast area, though
initialization looks close enough for some possible discrete
cells in at least the west before storms may eventually
organize into a line. Shear is expected to be a bit stronger by
evening, especially in the low levels. All hazards will be
possible at first, likely transitioning to a wind and QLCS
tornado threat as the storms progress eastward if they develop
into a line. Still some time for the finer details of the severe
storm concern to change given the complexity of storm timing,
peak heating, effective boundaries, and so on. Overall though,
confidence is increasing in this second round of potential
severe storms for southern Wisconsin.

In between the two rounds of storms, there should be some breaks
in the clouds, allowing temps to warm towards 90 degrees most
places. Given dewpoints in at least the low 70s, heat indices
may approach or hit 100 degrees, so this period is still being
watched for a potential Heat Advisory.

Showers and storms Wed should exit the east by early Wed night,
with dry weather likely overnight into early Thursday. The main
shortwave and cold front are expected approach from the west
during the day Thursday, with another round of storms possible
as this better forcing moves through the area. Model instability
points to the south half of the forecast area as having the
best chance to see another round of storms, with a decent shot
at another severe potential if convection rolls through the
area. Deep layer shear is looking a bit stronger Thu than Wed,
with ample instability and solid lapse rates as well. Warm and
humid conditions are expected again Thursday, with the warmest
conditions likely in the east.

Dry weather is expected Friday behind the departing low and
front, with high temps back towards normal values. Dewpoints
will be lower as well, likely settling into the 50s most
places.

Saturday through Monday are trending a bit more active, with
multiple shortwaves likely to move through the region during
this period. There is a lot of spread with the timing and
placement of individual waves along with the depth of the
moisture, amount of instability, etc. Kept precip chances on the
lower end for now given the lingering uncertainties.

DDV

&&

.AVIATION...
Issued 542 AM CDT Tue Jun 9 2026

Ceilings at MVFR levels (IFR in a few spots) will gradually
improve to VFR by late afternoon. Expect isolated showers with a
slight chance of lightning, mainly through midday.

Dense fog developed along the shoreline of Sheboygan county and
spread inland overnight. Expect the land-fog to diminish by mid
morning. More widespread marine fog is expected late this
afternoon through tonight, so lakeshore areas may be affected
by some of it drifting inland (MKE, RAC, ENW, ETB, SBM) as the
lake breeze develops.

Scattered storms are possible early Wednesday morning. Severe
hail and winds would be the hazards. Additional rounds of
storms, possibly severe, are expected Wednesday afternoon
through Thursday.

Cronce

&&

.MARINE...
Issued 542 AM CDT Tue Jun 9 2026

Light and variable winds will increase and become northerly by
this evening as low pressure of 29.9 inches crosses the center
part of Lake Michigan. Dense fog is expected at times through
tonight due to a warm and humid airmass over the relatively cool
waters. A Marine Dense Fog Advisory is in effect for central
portions of the lake at this time. An advisory that covers more of
the lake may be needed tonight. There is a chance of showers with
a few rumbles of thunder through tonight as well.

Breezy southerly winds are expected Wednesday and Thursday as
strong low pressure around 29.2 inches tracks from southern
Saskatchewan to Hudson Bay. Multiple rounds of showers and storms
are likely during this time, along with a chance for severe
storms. West to southwest winds and dry weather are then expected
Friday behind the departing low.

Cronce

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Dense Fog Advisory...WIZ052 until noon Tuesday.

LM...Dense Fog Advisory...LMZ366-LMZ565-LMZ567-LMZ643-LMZ669-LMZ868-
     LMZ870 until noon Tuesday.

&&

$$

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