337
FXUS63 KMKX 222132
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
332 PM CST Mon Dec 22 2025

.KEY MESSAGES...

- Drizzle is expected to move into the area this evening (about
  60 percent or higher chances) before ending later tonight.
  Some light freezing drizzle is possible over northern portions
  of the area during this period, if temperatures can drop to
  the freezing mark. If so, slick spots may occur on untreated
  surfaces in these areas tonight into early Tuesday morning.

- Temperatures continue to trend well above normal through the
  end of the week.

- Chances (about 30 to 50 percent) for light rain or drizzle in
  southeast Wisconsin Wednesday evening, with rain likely (about
  50 to 70 percent chances) area wide Christmas night.

&&

.SHORT TERM...
Issued 332 PM CST Mon Dec 22 2025

Tonight and Tuesday:

Steady warm air advection will continue into this evening,
before a weak cold front moves east through the area later
tonight. Most model forecast soundings continue to show a
fairly moist to saturated low level layer developing by early
this evening, with the middle to upper levels drying out and
removing ice crystals. Thus, drizzle is expected to move
through the area into this evening before ending later tonight
with the frontal passage.

There may be some light freezing drizzle as well over northern
portions of the area during this period, if temperatures can
drop to the freezing mark. There is some uncertainty if
temperatures will actually drop much tonight in this area before
the frontal passage, as the steady warm air advection may keep
temperatures relatively steady.

Temperatures will be close, so have kept in some light freezing
drizzle in the forecast for the northern parts of the area
north of Madison and Milwaukee. Will message this light freezing
drizzle potential with slick spots in the Weather Story
graphic. There may be some refreeze potential in this area as
well for the Tuesday morning commute, as temperatures remain
near freezing.

West northwest winds will then linger through Tuesday, with
perhaps some scattering out of the clouds by later in the day.
Highs will remain mild, from the upper 30s north to the lower to
middle 40s southeast.

Wood

&&

.LONG TERM...
Issued 332 PM CST Mon Dec 22 2025

Tuesday night through Monday:

The extended models have fairly good agreement for much of the
week but then diverge for the weekend as cyclogenesis may occur
over the Great Lakes and Ontario.

For Tue nt, a sfc ridge over nrn MN and adjacent Canada will
build sewd to the nrn Great Lakes and MI by 12Z Wed. Thus the
sfc ridge will shift across srn WI with temps dropping into the
20s for lows. Ssely sfc winds and warm advection will begin on
Wed as the high moves away and a wave of low pressure tracks
from the central Great Plains into the Ohio Valley through Wed
nt. In addition, another sfc trough will track across the nrn
Great Lakes and nrn WI during this time. Aloft a vorticity
maximum is expected to traverse across srn WI during this time
in conjunction with low to mid level warm, moist advection.
Either drizzle or very light rain may develop (30-50%) for Wed
evening over se WI with slight chances (20%) elsewhere. A weak
cold front will then follow.

Large polar high pressure will then follow across Ontario with
shortwave ridging aloft over srn WI on Thu. Nly winds will
shift ely but relatively mild temps will continue. For Thu nt, a
shortwave trough will track from the nrn Great Plains toward the
nrn Great Lakes, while at the sfc a wave of low pressure will
track from the central Great Plains across the nrn Ohio Valley
through Fri. The warm, moist advection will bring 50-70% chances
for rain late Thu nt, possibly lingering into Fri AM.

A more significant upper trough will then move ewd across srn
Canada inducing some degree of cyclogenesis over Ontario or the
Great Lakes for the weekend. There is wide spread with the
details, but strong cold advection and a polar airmass will
likely follow for Sat nt-Mon. Relatively mild temps continue
through Sat then much colder.

Gehring

&&

.AVIATION...
Issued 332 PM CST Mon Dec 22 2025

Modest south winds will continue into this evening, before a
weak cold front moves east through the area later tonight. Winds
will then shift southwest behind the front and west northwest on
Tuesday.

Ceilings should lower to 2500 to 3000 feet AGL into this
evening, along with steady drizzle into later tonight. There may
be some visibility reductions to perhaps 3 to 5 miles in the
drizzle, though confidence is too low to add at this time.

There may be patchy light freezing drizzle as well in northern
portions of the area, perhaps affecting Sheboygan. This is where
surface temperatures may drop to the freezing mark. There is
uncertainty if this may occur, so will leave any of the light
freezing drizzle mention out of the Sheboygan TAF for now.

Once the cold front moves through, ceilings may drop to 2500
feet AGL at times once again into Tuesday morning, though some
uncertainty with this happening as well. Ceilings should rise to
above 3500 feet AGL by later Tuesday morning into the afternoon.
The ceilings may scatter out later in the day.

Wood

&&

.MARINE...
Issued 332 PM CST Mon Dec 22 2025

A Small Craft Advisory remains in effect into this evening from
Port Washington northward, mainly for elevated waves of 4 to 6
feet.

South winds this evening will shift southwest later tonight and
west on Tuesday, as low pressure around 29.8 inches moves into
Ontario. Winds will shift west northwest by Tuesday afternoon,
as high pressure around 30.4 inches moves from North Dakota into
northern Minnesota. Winds will subside Tuesday night, as the
high crosses Lake Michigan. These winds will shift out of the
southeast Wednesday, as the high moves east of the region.

Another stronger high around 30.5 inches will move east across
southern Manitoba into Ontario Wednesday night into Christmas
Day, with winds steadily increasing out of the northeast to
east.

Wood

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Small Craft Advisory...LMZ643 until 9 PM Monday.

&&

$$

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