Menomonee Falls, Wisconsin 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

943
FXUS63 KMKX 201604 AAA
AFDMKX

Area Forecast Discussion...UPDATED
National Weather Service Milwaukee/Sullivan WI
1004 AM CST Sat Dec 20 2025

.KEY MESSAGES...

- A wintry mix of patchy freezing drizzle, drizzle, and very
  light snow may occur through the morning. Minimal if any
  impacts are expected, as the low levels remain quite dry.

- Blustery conditions are expected tonight, with wind chills
  falling below zero by daybreak.

- Chances (about 25 to 40 percent) for light rain and light snow
  Sunday night into Monday, particularly to the north of
  Interstate 94 and US Highway 18.

- Temperatures trending well above normal Tuesday through
  Christmas Day.

&&

.UPDATE...
Issued 1004 AM CST Sat Dec 20 2025

Low level frontogenesis response ahead of the advancing cold
front may continue to bring a wintry mix of patchy freezing
drizzle, drizzle and very light snow to the area through the
rest of this morning. This is battling very dry air in the low
levels, so not much is reaching the ground, and what does is
very light. So, minimal to no impacts are anticipated from this
activity.

The cold front will push to the east of the area early this
afternoon, with gusty west to northwest winds developing. This
will bring in cold air advection and falling temperatures, which
will continue into tonight. Lows tonight should bottom out in
the single digits above zero, with wind chills later tonight and
Sunday morning in the single digits below zero to around 10
below zero. Coldest values will be in the northern parts of the
area.

High pressure passing by to the southwest of the area later
tonight into Sunday should bring dry conditions with gradually
weakening winds. Highs Sunday will be in the lower to middle
20s.

Wood

&&

.SHORT TERM...
Issued 348 AM CST Sat Dec 20 2025

Today through Sunday:

Synopsis/Mesoanalysis: GOES water vapor imagery shows an upper
trough along the Manitoba-North Dakota border early this morning.
Immediately downstream of the wave, surface analysis places an area
of low pressure along the Manitoba-Ontario border. An Arctic cold
front has been analyzed near the low, with 2 AM observations placing
the boundary from western Minnesota into central Nebraska. High
pressure has shifted east into the Ohio River Valley, leaving
southern Wisconsin within broad southerly flow and steady warm
advection early this morning. Said warm advection will continue into
this morning, with many locations climbing into the low to mid 30s.
The aforementioned surface low will quickly shift toward Lake
Superior this morning, pushing its attendant Arctic cold front
through southern Wisconsin by the early afternoon hours. Lift
along/ahead of the front will support light wintry mix potential as
this occurs, with drizzle, freezing drizzle and snow being the
favored precipitation types. A dusting of snow is possible as wintry
precip moves through the area. A light glaze of ice can`t be ruled
out, particularly on elevated and untreated surfaces in east-central
Wisconsin. Conditions will quickly dry out by mid-late afternoon,
with post-frontal cold air advection & gusty northwest winds leading
to chilly conditions tonight. Winds will taper Sunday as high
pressure builds into the western Great Lakes.

Today: Wintry precip potential will start to increase by daybreak
given continued warm advection/isentropic ascent in the 1000-850 mb
layer & increasing lift ahead of the approaching front. Best precip
chances through sunrise will be to the north of I-94 & US-18, where
overlap of the aforementioned forcing mechanisms will be
greatest. Anticipate that some precip could fall as freezing
drizzle given a lack of cloud ice in the prefrontal environment,
with a very light glaze of ice accumulation possible on
elevated and untreated surfaces. Will then see precip potential
overspread all of southern Wisconsin by mid-late morning as the
cold front enters & passes through the region. Depending on how
mild temps get pre-front, could see some of this precip begin as
rain or rain/snow mix in more southern locations, with a quick
change to all snow during/after the frontal passage given deep
frontogenesis & affiliated dynamic cooling. Can`t rule out a
quick dusting of snow on grassy surfaces. Precip will shut off
quickly during the early afternoon as the cold front departs &
drier air advects in from the northwest. While snow/ice
accumulations will be minor in today`s precip, those planning to
be on the roads should budget a few extra minutes of travel
time.

Tonight: Gusty northwest winds & arriving Arctic air will lead to
chilly conditions areawide. Expect lows in the single digits in most
locations, with wind chills falling below zero by sunrise. Bundle up
if heading out tonight & early Sunday morning.

Quigley

&&

.LONG TERM...
Issued 348 AM CST Sat Dec 20 2025

Sunday night through Friday:

Synopsis: An upper disturbance is progged to track across the
western Great Lakes Sunday night through Monday morning, bringing
chances for light snow or rain/snow mix to areas primarily north of
I-94 & US-18. Following a brief cold frontal passage Monday night
into Tuesday, winds will turn out of the south to southwest during
the middle to late week period. Said winds will advect a mild air
mass into the western Great Lakes, with temperatures expected to
climb well above normal by Christmas Day. Light rain is possible
(~15-30% chances) Christmas Eve into Christmas Day as a second
disturbance moves across the western Great Lakes.

Sunday Night into Monday: The next disturbance is forecast to move
in from the Northern Plains during this time frame. Global
deterministic & ensemble guidance continues to paint a more northern
track to the system, putting northern Wisconsin & Michigan`s Upper
Peninsula in the best position for light snow or rain/snow mix.
Nevertheless, areas to the north of I-94 and US-18 remain on the
southern fringes of model frontogenesis & warm advection fields, so
have maintained chance (~25-40%) precip probabilities from the NBM
in the overnight update. Expect that any accumulation in snow or
rain/snow mix would be very light, with current probabilistic snow
guidance showing only a 20-40% chance of a dusting across our
northern counties.

Tuesday through Friday: Temperatures will steadily climb upward
through Christmas Day thanks to persistent south to southwest
surface flow. Currently expect Christmas Day to be the warmest day
of the period, with probabilistic temperature guidance currently
indicating medium (~40-65%) potential for highs at/above 50. Some
light precip is possible Christmas Eve into Christmas Day as the
next disturbance moves through, with all rain being favored given
the mild conditions.

Quigley

&&

.AVIATION...
Issued 1004 AM CST Sat Dec 20 2025

A wintry mix of patchy freezing drizzle, drizzle and very light
snow may occur through the rest of this morning, as a cold
front moves through. This is battling very dry air in the low
levels, so not much is reaching the ground, and what does is
very light. So, minimal to no impacts are anticipated from this
activity.

The cold front will push to the east of the area early this
afternoon, with gusty west to northwest winds developing. This
will bring in colder air, which will continue into tonight.
Skies will clear out this afternoon and remain clear tonight
into Sunday morning.

High pressure passing by to the southwest of the area later
tonight into Sunday should bring dry conditions with gradually
weakening winds. These winds should shift to the southwest and
south by later Sunday and remain light. These winds should
slowly increase Sunday evening.

Wood

&&

.MARINE...
Issued 348 AM CST Sat Dec 20 2025

1022 mb high pressure currently centered over Ohio will continue to
drift east early this morning, while 992 mb low pressure continues
to move east into Ontario. The progression of the low and the high
will result in increasing southerly winds across the open waters
from predawn through late morning today. Gusts will periodically
exceed gale force, with a Gale Warning having gone into effect at 2
AM CST early this morning. A brief decrease in gusts may occur from
late morning into the early afternoon as a cold front approaches and
begins to cross Lake Michigan. The passing boundary will result in a
west-northwest wind shift across the waters. West-northwest gusts
will then quickly increase in the wake of the passing front by late
afternoon, when a return of widespread gales is anticipated across
the open waters. Gales will continue into the predawn hours Sunday,
with the ongoing Gale Warning remaining in effect until 3 AM CST.
Snow and rain-snow mix will accompany the approaching/passing cold
front this morning and afternoon. Areas of moderate freezing spray
are expected this evening as Arctic air settles in behind the
departed front. Pockets of heavy freezing spray are possible, though
conditions aren`t expected to be widespread enough to warrant
headlines at this time. Trends will continue to be monitored in the
coming forecasts.

Winds will steadily taper over the open waters Sunday morning and
afternoon as 1028 mb high pressure settles into the western Great
Lakes. Said high will move east of Lake Michigan Sunday night into
Monday as 1008 mb low pressure builds in the northern Great Plains,
resulting in a south to southwest wind shift. 25-30 knot gusts are
possible during the day Monday, though widespread gale potential is
low at this time. Trends will continue to be monitored. Winds will
shift out of the west-northwest and weaken Tuesday through Tuesday
night as the next area of high pressure moves into the northern
Great Plains.

Southerly wind gusts continue to steadily increase this morning in
nearshore zones, where a Small Craft Advisory remains in effect.
Winds will briefly subside from late morning through early afternoon
as a cold front approaches from the northwest. Light rain, snow, and
freezing drizzle are possible as the front approaches and passes
through the region. Winds will shift out of the west-northwest
behind the departing surface front, becoming gusty by late
afternoon. Gales are anticipated as this occurs, and are forecast to
continue into early Sunday morning. A Gale Warning thus remains in
effect from 3 PM CST today until 3 AM CST Sunday in all nearshore
zones. Areas of light to moderate freezing spray are possible as
Arctic air moves in behind the cold front. While gusts will steadily
decrease Sunday morning, a brief period of Small Craft Advisory
conditions is possible following the expiration of the Gale Warning
through sunrise. If necessary, these conditions will be addressed
with headlines in later forecasts. Additional Small Craft Advisory
conditions are possible Monday and Monday night.

Quigley

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646 until 3 PM
     Saturday.

     Gale Warning...LMZ643-LMZ644-LMZ645-LMZ646...3 PM Saturday to
     3 AM Sunday.

     Gale Warning...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-
     LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-
     LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 until 3 AM
     Sunday.

&&

$$

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