NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 130007
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
707 PM CDT Tue May 12 2026

.KEY MESSAGES...

- A passing cold front this afternoon may bring some
  thunderstorms (30 to 50 percent chances), mainly along and
  southeast of a line from Darlington to Sheboygan. Gusty winds
  and small hail may occur with the stronger storms, if they
  develop.

- A Wind Advisory is in effect into the early evening as gusty
  winds mix down to the surface.

- A Gale Warning remains in effect for the middle third of the
  open waters of Lake Michigan into late this afternoon, as well
  as the nearshore waters from Sheboygan to Port Washington.

- Relatively warm and humid conditions with increasing storm
  chances returns Thursday night into the weekend.

&&

.UPDATE...
Issued 657 PM CDT Tue May 12 2026

Clearing skies behind this morning's rain allowed for deep
mixing to occur late this afternoon. This mixing tapped into a
strong jet aloft along and ahead of an approaching front from
the northwest. Gusty winds up to 40 knots have been reported
over southern WI and a Wind Advisory will remain in effect over
southern WI until daytime mixing ceases after sunset.

As of now, the front is roughly located from Sheboygan Co to
Rock Co. Spotty showers and a few rumbles of thunder have formed
over east central WI. A downward trend in cumulus clouds over
southeast Wisconsin suggests that most of the activity along
the front will remain confined to areas north of I94 as the
front moves east-southeast and clears the area after sunset.
Gusty winds will be the main hazard with any showers and storms
tonight as the rain will efficiently mix higher winds down to
the surface. Otherwise small hail will be a secondary threat
with any well established updrafts.

CMiller

&&

.SHORT TERM...
Issued 118 PM CDT Tue May 12 2026

Tonight through Wednesday night:

Showers along and south of I-94 early this afternoon will wind
down by mid-afternoon, with some clearing continuing to work in
from the northwest. Given enough afternoon heating, a few
thunderstorms may pop along a cold front late afternoon into
early evening, mainly along/east of a line from Darlington to
Sheboygan. A stronger storm or two is not out of the question
given sufficient instability, as there will be plenty of shear
to work with. Small hail and gusty winds would be the main
concerns.

Skies will clear out for a time behind the front this evening,
though cloud are expected to fill in behind the front/low
tonight into Wednesday with a cooler airmass in place. Temps
will be a bit cooler tomorrow behind the front, but highs will
still be within a couple degrees of normal.

DDV

&&

.LONG TERM...
Issued 118 PM CDT Tue May 12 2026

Thursday through Tuesday:

High pressure will clear skies and light winds on Thursday, with
a lake breeze likely late morning into the afternoon. Southerly
winds will bring milder conditions to the area, with highs
approaching or hitting 70 away from the lake. Cooler conditions
are expected near the lake due to the onshore winds for much of
the day.

Moisture will increase later Thursday into Thursday night, with
a shortwave and area of warm advection aloft expected to bring
a round of showers and storms overnight into at least early
Friday. Additional shower/storm chances will be possible later
Fri into Fri night as another wave rolls through.

Saturday is currently looking mainly dry, as precipitable water
values drop to around 0.5" under a weak surface high per the
latest ECMWF and GFS deterministic runs. Deeper moisture then
makes a quick return Sunday into Monday, with precipitable
water values rising to the 1.5-1.7" range. Multiple waves are
expected to lift through the area during this period, bringing
at least a couple rounds of shower/storm chances. Above normal
temps are also expected late weekend into early next week.

DDV

&&

.AVIATION...
Issued 659 PM CDT Tue May 12 2026

Gusty southwest wind will continue over southeast Wisconsin
while gusty northwest winds will continue for KMSN and points
westward as a cold front works through the area. The front is
projected to clear the area by 03z tonight and all areas in
southern WI should feature northwest winds. A few storms will be
possible along the front this evening, mainly around KFDL and
KSBM. VFR conditions will likely prevail save for any drops in
flight category around showers and storms.

SCT to BKN clouds are expected to persist in some capacity
overnight. MVFR ceilings may move in around daybreak Wednesday over
east central WI for KSBM while areas south toward KMSN, KUES,
and KMKE see low VFR ceilings. Gusty northwest winds will
persist on Wendnesday amid dry conditions.

CMiller

&&

.MARINE...
Issued 118 PM CDT Tue May 12 2026

Low pressure of 29.7 inches over northern Wisconsin early this
afternoon will reach northern Lake Michigan early this evening
and Lake Huron by early Wednesday morning. An associated cold
front will approach the lake today, moving through this evening.
Gusty south to southwest winds will continue today as the front
approaches, with a few gales possible across central and
northern portions of the lake through late afternoon. Showers
and a few storms will be possible ahead of and along the front
today.

Gusty west to northwest winds will arrive behind the cold front
tonight into Wednesday. Gusts could approach gale force for a time
tonight into early Wednesday, but are expected to mainly stay
below gales. Lighter northerly winds are then likely Thursday as
high pressure of 30.2 inches moves overhead. Breezy southerly
winds are expected to develop Friday ahead of the next approaching
low pressure system.

DDV

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Wind Advisory...WIZ046-WIZ047-WIZ051-WIZ052-WIZ056-WIZ057-
     WIZ058-WIZ059-WIZ060-WIZ062-WIZ063-WIZ064-WIZ065-WIZ066-
     WIZ067-WIZ068-WIZ069-WIZ070-WIZ071-WIZ072 until 8 PM
     Tuesday.

LM...Gale Warning...LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-LMZ669-
     LMZ671-LMZ673-LMZ675-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876
     until 11 PM Tuesday.

     Gale Warning...LMZ643-LMZ644-LMZ645-LMZ646 until 9 PM Tuesday.

     Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 4 PM
     Wednesday.

&&

$$

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