NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 302048
AFDMKX

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

.KEY MESSAGES...

- Widespread light snow (0.5 - 1.5 inch) late this afternoon
  and evening for all of southern WI with highest amounts over
  ern and central WI.

- Another round of light snow late Wednesday morning and
  afternoon with amounts ranging from a dusting to under 1 inch.
  Best chance for snow amounts around an inch will be south of
  Madison.

- Single digit temps and sub-zero wind chills (-5F to -15F)
  expected Wednesday night into Thursday morning


&&

.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 248 PM CST Tue Dec 30 2025

Light snow and MVFR Cigs and Vsbys, with periods of 1SM -SN,
to develop late this afternoon and last into the evening. The
snow will end late this evening with areas of MVFR Cigs
continuing then more light snow possible for Wednesday. Vsbys
with the snow on Wednesday could drop to 1-2SM at times.

Gehring

&&

.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...None.
LM...None.
&&

$$

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