NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 310216 AAA
AFDMKX

Area Forecast Discussion...UPDATED
National Weather Service Milwaukee/Sullivan WI
816 PM CST Tue Dec 30 2025

.KEY MESSAGES...

- Freezing drizzle to cause slick roads across south central
  Wisconsin until later this evening. A Winter Weather Advisory
  is in effect for this area.

- Widespread light snow will linger until later this evening for
  mainly southeast and east central Wisconsin.

- Another round of light snow is expected later Wednesday
  morning and afternoon, with amounts ranging from a dusting to
  under 1 inch. The best chances for snow amounts around an
  inch will be south of Madison.

- Single digit temps and wind chills of 5 below to 15 below zero
  are expected overnight New Years Eve into New Years Day.

&&

.UPDATE...
Issued 816 PM CST Tue Dec 30 2025

A Winter Weather Advisory has been issued until 10 PM CST this
evening for south central Wisconsin, as freezing drizzle has
resulted in slick roads and travel impacts. This freezing
drizzle was being driven by 925 mb warm air advection with no
ice crystals available from western to south central Wisconsin.

This upward vertical motion should shift southeast of the area
by later this evening, with drier air in the low levels moving
southeast toward the area. So, the freezing drizzle should end
by later this evening. Will watch radar and observation trends
and see if the advisory needs to be extended beyond 10 PM CST
this evening.

There may be some light freezing drizzle that occurs overnight
toward the Dells and Montello, if there is enough lingering
moisture and upward motion. Will continue to look at this
potential with the 00Z suite of models.

The light to moderate snow continues across east central and
southeast Wisconsin, as the main 500 mb vorticity maximum shifts
through the region with some 850 mb to 700 mb warm air
advection. This upward vertical motion will continue to slide
southeast of the area by later this evening, so the snow should
come to an end as well.

Wood

&&

.SHORT TERM...
Issued 248 PM CST Tue Dec 30 2025

Tonight through Thursday:

An initial round of light snow has mostly fizzled out but new
development, from a stronger shortwave trough currently over ne
MN, is occurring across nrn and central WI. The upper wave will
quickly track to east central WI by early this evening then to
the border of lower MI with Ohio and nw IN by 06Z Wed. A wnwly
LLJ of 40 kt will nose sewd from se MN into sw WI ahead of the
upper wave; thereby enhancing warm advection over all of srn WI,
and generating 850 mb frontogenesis over ern WI. Thus the
better lift and snowfall rates will be late this afternoon and
early evening. Overall expect QPF (0.1 or less) and snowfall to
still be light and will range from 1/2 inch or less of snow
accum over sw WI to 1.5 inches toward east central WI. Will
continue to message the snowfall and potential travel hazards
for the late afternoon and evening commute. The snow will then
end from west to east around 01-05Z Wed.

Yet another stronger shortwave trough will then track sewd
over Ontario and the nrn Great Lakes on Wed in response to an
incredibly deep cyclone of 953 MB, which will occlude and
retrograde across nrn Quebec and Hudson Bay through Thu. A polar
cold front will accompany the aforementioned upper wave and
will shift swd across the region from late Wed AM into the
afternoon. Low to mid level frontogenesis along a strong
tropospheric temperatures gradient will likely generate more
light snow during this time. The Fgen values are fairly low and
believe snow accums will remain light. Cold advection to then
prevail Wed nt then slow down on Thu as high pressure tracks
from srn MN to the Ohio River Valley. Lows New Year's morning
will range from 1 below to 6 above zero with high temps climbing
into the teens. Wind chills will bottom out at 5 below to 15
below zero around sunrise New Year's Day.

Gehring

&&

.LONG TERM...
Issued 248 PM CST Tue Dec 30 2025

Thursday night through Tuesday:

Troughing over the northeastern United States and eastern Canada
and northwest flow will keep us cold and dry to start the
extended period. Overnight lows Thursday night through Saturday
night will range from the single digits to low 10s with daytime
temps Friday and Saturday in the upper teens to low 20s. This will
be accompanied by high pressure arching from North Dakota into the
eastern Corn Belt.

Temperatures moderate toward normal in the mid to upper 20s on
Sunday as the center of the high pressure passes over the state
and moves southeast into Indiana, allowing for south winds to
return. Sunday evening, the NBM feathers slight chance PoPs (10 to
20%) into the area as global models vary widely on the placement
of a passing, WAA-driven wave. The current spread for the expected
snow band is as far south as the WI/IL border to as far north as
Lake Superior, so nothing is set in stone for this wave at this
time.

Otherwise the start of next week looks quiet with temperatures
remaining around normal.

CMiller

&&

.AVIATION...
Issued 816 PM CST Tue Dec 30 2025

Freezing drizzle should linger at Madison and Janesville until
later this evening, before dissipating. Low ceilings below 1000
feet AGL may occur at times, though should mostly be 1000 to
1500 feet AGL into the overnight hours. There may be some light
freezing drizzle that occurs overnight north of Madison. Light
northwest winds are anticipated overnight into early Wednesday
morning.

The light to moderate snow continues across east central and
southeast Wisconsin including Sheboygan, Waukesha, Milwaukee and
Kenosha. The snow should come to an end as well across these
areas by later this evening. Light northwest winds are
anticipated overnight into early Wednesday morning, with
ceilings in the 1000 to 1500 foot AGL range.

Ceilings should generally stay in the 1000 to 2000 foot AGL
range Wednesday into Wednesday evening, with northwest winds
gradually increasing. An area of light snow will develop by
midday across most of the area, except Sheboygan where some
drier air may limit the snow.

The snow should linger through the afternoon and end by early
Wednesday evening. Visibility should be in the 1 to 2 mile range
with the snow, with snowfall rates of up to one quarter inch
per hour. The snow character will be fluffy and powdery.

Wood

&&

.MARINE...
Issued 248 PM CST Tue Dec 30 2025

Modest west to northwest winds will prevail this afternoon and
tonight as strong low pressure remains over Quebec and a weak
cold front moves across Lake Michigan. The strong low over
Quebec will then move over eastern Hudson Bay for Wednesday into
Thursday which will aid in moving a stronger cold front across
Lake Michigan. Thus brisk northwest winds and moderate freezing
spray is expected for Wednesday through Thursday morning. A few
gale force wind gusts will be possible over far northern Lake
Michigan Wednesday into Wednesday evening. Modest to brisk west
to northwest winds will then continue the remainder of the week.
A Small Craft Advisory may be needed Wednesday afternoon and
night from Sheboygan to Winthrop Harbor, but confidence is low
at this time.

Gehring

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Winter Weather Advisory...WIZ046-WIZ047-WIZ056-WIZ057-WIZ062-
     WIZ063-WIZ067-WIZ068-WIZ069 until 10 PM Tuesday.

LM...None.
&&

$$

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