NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 090350 AAA
AFDMKX

Area Forecast Discussion...UPDATED
National Weather Service Milwaukee/Sullivan WI
950 PM CST Sat Nov 8 2025

.KEY MESSAGES...

- Mainly light snow, with rain/snow mix near Lake Michigan,
  lingering before ending northwest to southeast later this
  evening and overnight. Minor, slushy accumulations less than
  one inch on elevated and grassy surfaces.

- Cold, below normal temperatures for Sunday, with lows in the
  20s and highs in the 30s.

- There is a growing potential for a lake effect snow band to
  impact southeastern Wisconsin Sunday night into Monday
  morning. The difference between a dry forecast and one with
  several inches of accumulating snow will be based on the wind
  direction over the Lake Michigan and duration.

- Temperatures return to near normal mid-week and are trending
  above normal for the end of the week.

&&

.UPDATE...
Issued 950 PM CST Sat Nov 8 2025

Mainly light snow is occurring across southern Wisconsin, with a
light rain and light snow mix across areas near Lake Michigan
with milder temperatures there. This activity should gradually
shift southeast and out of the area overnight. Far southeast
areas near the lake may see some rain/snow showers linger
overnight with a lake effect band, before it shifts further
east.

Wet, slushy accumulations up to an inch is possible on grassy
and elevated surfaces, with mainly wet roads. Some slick spots
may still occur on elevated surfaces as temperatures continue to
drop overnight.

Gusty north to northwest winds will develop overnight into
Sunday, with brisk and cold temperatures expected. Lows in the
20s overnight with highs only in the middle 30s are anticipated
on Sunday. Wind chills will be in the teens overnight and teens
to lower 20s Sunday.

Wood

&&

.SHORT TERM...
Issued 306 PM CST Sat Nov 8 2025

Tonight through Sunday:

Overall, the trend continues to favor the better upper-level forcing
(+100kt 250mb jet and 500mb dCVA) remaining south of the WI/IL
border as the upper-level trough digs across the Midwest. This
aligns well with the surface low currently tracking along the IA/MO
border into central IL. Beginning to see light rain and drizzle
spread across southwestern WI late this afternoon and will continue
to spread eastward through the evening. Expecting as the temps drop
as we head into the evening, the freezing height currently between
1.4-2kft will follow suit and lower while saturating toward the
surface. In the next hour or two, will begin to see rain transition
to a wintry mix of rain and snow for inland areas of southern WI.

Meanwhile areas closer to Lake Michigan may hold onto the rain a bit
longer given the warmer lake temps and onshore, but eventually will
see a transition to wintry mix and even snow later this evening (02z-
04z) Overall, much of the area will see the first snowflakes of the
season, generally looking at fairly minor accumulations (<1").
Areas along/north of a line from WI Dells to Port Washington may
see a few flakes, but not expecting much in the way of
accumulations given it will have to battle more dry air and
farther from the forcing. As you go south will begin to see a
bit more accumulation tonight, but will have to contend with the
warmer ground temps and snow rates of <0.5in/hr, thus slushy
accumulations mainly expected on elevated and grassy surfaces.
Highest accumulation around half an inch approach 1 inch will be
closer to the WI/IL border.

Snow chances diminish overnight into Sunday as winds turn more
northerly behind the departing low pressure system. Strong push of
CAA will also bring in dry, cold, brisk Canadian airmass for Sunday.
Overnight temps tonight fall into the 20s by early Sunday morning as
clouds clear, but daytime temps are only looking to warm into the
low to mid 30s Sunday afternoon. So we will getting a taste of
winter.

Sunday afternoon through Sunday Night:

There will be another taste of winter later Sunday into early Monday
morning as a deepening trough digs down across the Upper Great
Lakes Region through the day into Monday. May see some scattered
light snow across southern through the afternoon, but the main
focus will be on the lakeshore areas. This deepening trough
paired with the cold airmass and northerly winds over Lake
Michigan will set up a pattern favorable for an early season
mid-lake lake effect snow band.

Models have been picking up on this stronger, deepening trough since
yesterday afternoon and the trend continues today. Given Lake
Michigan surface temps still in the 50-55F range, delta T between
SST and 850mb will range from 20-26C. Combined with fetch across the
north-south extent and that trough, trends support moderate to heavy
snow accumulations with wherever this band will set up. Now the big
question is will this lake effect snow band waffle enough and impact
southeastern WI.

The most likely scenario is winds stay north enough to keep this
band offshore and impacting southern tip of Lake Michigan in
northern IN, with maybe the band glancing portions of southeaster WI
sticking out more into Lake Michigan (e.g far eastern sheboygan,
Racine, and Kenosha). In this case could see a these far eastern
areas pick up a couple of inches of snow overnight Sunday into early
Monday, while areas just west toward I-41 may see just some light
snow and/or even stay dry.

However, there is a suite of of models (12z ARW, 12z NSSL, 12/15z
RAP, and a couple rounds of the HRRR, as well as the 12z GFS)
that do show more of a north-northeastern wind field over the
Lake along with hints of a meso-low developing. IF this
scenarios pans out there is a potential for a a couple hour
period producing more widespread lake effect snow to spread
across east central and southeastern WI with several inches of
accumulating snow. While this is a more recent trend being
picked up by the models, it is not out of the questions given
how potent of a system this may be. If these trends continue,
then can expect travel impacts overnight Sunday into Monday.
Also likely to be a wetter type snow so accompanying impacts to
powerlines and trees would be possible.

Overall, the Sunday night into Monday period bears watching over the
next day as a 10-20 degree shift in the winds can be the determining
factor between a dry forecast and impactful accumulating snow.

Wagner

&&

.LONG TERM...
Issued 306 PM CST Sat Nov 8 2025

Monday through Saturday:

The upper-level trough bringing the weekend activity begins to shift
east out of the region for Monday. Southern WI will be influenced
from a gradually weaken surface high as it tracks from the Northern
Plains down through the lower Mississippi River Valley through
Monday night. Thus looking at drier conditions and lighter winds as
temps gradually warm back into the upper 30s approaching 40F for
Monday.

While the influence from the high lessens into Tuesday and expecting
see a warm up through the end of the week. Tuesday into Wednesday
mid-range models suggest an upper-level trough to track across Upper
Midwest and northern Great Lakes region. However the associated
surface low is progged to remain well north of the area, resulting
in southern WI firmly settled into the warm side of this system with
prevailing southern winds. Will see this system drag a cold front
across WI later Tuesday into midweek and will be accompanied by
another round of showers along the frontal boundary, thus increased
precip chances. Given the warmer trend expecting the main precip
type to be rain, but if precip is delayed a bit later/overnight,
could also see a wintry mix of rain/snow with this round of activity
as well, but still a bit to far out to say with any certainty.

Behind this midweek cold front, not expecting a strong push of cold
air, in fact model trends favor temps to quickly recover through the
end of the week as upper-level ridge builds across the central
CONUS. Based on the NBM as well as the ENS and GEFS ensembles, there
is even an increase probability (>50%) of seeing well above normal
high temps for the end of the week with mid to upper 50s and even
cracking back into the 60s toward next weekend possible.

Wagner

&&

.AVIATION...
Issued 950 PM CST Sat Nov 8 2025

Mainly light snow is occurring across southern Wisconsin, with
a light rain and light snow mix across terminals close to Lake
Michigan with milder temperatures there. This activity should
gradually shift southeast and out of the area overnight.
Visibility of 1 to 4 miles and ceilings of 800 to 1800 feet AGL
are expected with the light snow in southern portions of the
area, including Janesville and Kenosha. Ceilings and visibility
values will be higher to the north.

The Kenosha and perhaps Milwaukee terminals may see some
rain/snow showers linger overnight with a lake effect band,
before it shifts further east. Any wet, slushy light
accumulations up to an inch would be on grassy and elevated
surfaces, with the runways and roads mainly just wet.

Gusty north to northwest winds will develop overnight into
Sunday, with a brisk and cold airmass expected. Ceilings should
scatter our for a time Sunday morning, before becoming more
broken around 5000 feet AGL Sunday afternoon. Scattered light
snow showers are also possible in the afternoon.

There is potential for a lake effect snow band to move southwest
and onshore across terminals close to Lake Michigan Sunday night
into early Monday morning. There is still uncertainty with if
and where exactly this lake effect snow band may occur, and how
much snow may fall. Kenosha would have the best chances for
this activity, with Milwaukee a somewhat lower chance. For now,
keep up with the forecast for this period.

Wood

&&

.MARINE...
Issued 950 PM CST Sat Nov 8 2025

Low pressure around 29.7 inches will move quickly from central
Illinois to the Ohio River Valley overnight. North to northwest
winds will increase overnight into Sunday behind the low. Gusts
Sunday and Sunday night will reach gale force, and a Gale
Warning is in effect for the southern half of the lake.

A Small Craft Advisory is in effect later tonight through
Monday evening for gusty winds and building waves. These
conditions may linger into the middle of next week.

Heavy lake effect snow is expected for Sunday night into Monday.

Winds will vary between northwest and southwest the first half
of next week, while remaining gusty through this period. Winds
may approach or reach gale force at times again Tuesday through
Wednesday.

Patterson/Wood

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Gale Warning...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
     LMZ779-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...6 AM Sunday
     to 6 AM Monday.

     Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646...3 AM
     Sunday to 9 PM Monday.

&&

$$

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