NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 271020
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
420 AM CST Thu Nov 27 2025

.KEY MESSAGES...

- Wind chills in the single digits tonight.

- Accumulating snow expected Saturday and Sunday. A Winter Storm
  Watch is in effect for most of southern Wisconsin.

&&

.SHORT TERM...
Issued 420 AM CST Thu Nov 27 2025

Today through Friday:

Overcast skies across most of southern Wisconsin are keeping
temperatures elevated in the mid to upper 20s early this
Thanksgiving morning. The continuous mixing over east central WI
where the skies are mostly clear has also helped to keep temps up,
despite this cold air mass that is settling into the region. Morning
wind chill values are in the mid teens. Highs today will be around
30, but with very little recovery in the wind chills.

Gusty northwest winds will remain elevated through the afternoon as
strong surface low pressure tracks from eastern Ontario to Quebec.
High pressure over the Dakotas will keep the pressure gradient on
the tighter side over Wisconsin today and actually into Friday
morning. This also means clouds will remain solid over the Upper
Great Lakes through this period.

One more weak shortwave will make its way from west central MN to
southern WI today, arriving by late morning. Expect one more burst
of gusty winds with peak gusts up to 35 mph near Lake Michigan
(better mixing) and 30 mph inland. We could see a period of light
snow showers or flurries through early afternoon since cloud bases
are sitting right within the snow growth zone.

While clearing seems probable for east central WI tonight, most of
southern WI will remain under overcast skies. This may keep temps up
a little higher than the upper teens that are currently in the
forecast.

Friday will begin with brisk northwest winds, especially for the
lakeshore areas, but they will diminish quickly at sunset as high
pressure takes over. A period of clear skies is still questionable
and not likely Friday night. If the low clouds can disappear, we
will still have some high clouds spreading in as the next system
approaches. Lows are forecast in the mid to upper teens, but these
may be a little too low if we have more widespread clouds.
Nevertheless, minimum wind chills will be 10 or lower.

Cronce

&&

.LONG TERM...
Issued 420 AM CST Thu Nov 27 2025

Saturday through Wednesday:

BLUF for Saturday- A prolonged snow event will begin in southern
Wisconsin early Saturday morning and exit Sunday morning. A period
of moderate snowfall rates (half inch to occasional inch per hour)
is expected Saturday afternoon and evening. This will be a plowable
snow and of the fluffier variety (13 to 16:1 snow ratio). The
probability of exceeding a storm total snowfall amount of 6 inches
is greater than 80 percent for most of southern Wisconsin. There is
even a chance that some areas could accumulate 12 inches of snow.
This will have an impact on post- Thanksgiving travel. A Winter
Storm Watch was collaborated with neighboring offices and the
Weather Prediction Center and is in effect from Midnight Friday
night through 6 AM Sunday morning. It includes the southern three
tiers of counties and leaves out the counties toward central WI.

The ensemble probabilities for snowfall totals greater than 6 inches
and for precip totals greater than 0.5" have shifted the highest
axis southward from the previous run. Thus, the farther north into
central Wisconsin, the lower the confidence in getting those higher
snowfall totals.

The reason for the southward shift appears to be related to the
southern portion of the upper wave slightly disjointed (less phased)
and a little faster. This pulls the wave into a negative tilt as it
crosses the Midwest and gives the surface low and associated precip
a slight nudge southward.

Here are the unknowns that will affect the snowfall totals in
southeast Wisconsin. Easterly winds on the north side of this
surface low will bring the warm Lake Michigan air onto the lakeshore
and keep temperatures on the mild side and lower the snow ratios
(wetter snow, lower amounts). However, the onshore flow can also
locally increase the precip amounts. As the low crosses northeast IL
and winds shift to the northeast, some lake enhancement may occur.
There may be an additional enhanced precip due to wrap-around within
the immediate vicinity of the low (due to frontogenesis) that would
also affect inland areas.
There are still many details that will come into better focus as we
near the arrival time of this event. Keep up with the forecast.

High pressure will move overhead Monday. A mid level trough will
slide across the center of the country Monday night, but it is
trending southward and the associated precip may miss southern WI. A
clipper system may bring light snow to WI on Wednesday, and perhaps
again Friday.

Temperatures will be much colder than normal across WI next week.
Highs around 20 and lows in the single digits will be the norm.

Cronce

&&

.AVIATION...
Issued 420 AM CST Thu Nov 27 2025

Cloud bases are sitting right around 3000 ft and will remain in the
2700 to 3300 ft range through much of the day. Clear skies over east
central WI are expected to fill in after daybreak. We could see
flurries at times, primarily late morning through early afternoon as
a weak upper wave makes its way through southern Wisconsin. This is
because the cloud bases are right within the snow growth region but
the cloud depths are not great. Winds will remain elevated with
gusts up to 35 kt until late afternoon.

The winds will gradually diminish tonight into Friday morning.
Clouds should remain in place for most of southern Wisconsin,
although east central WI has the best chance for clearing once
again.

Cronce

&&

.MARINE...
Issued 420 AM CST Thu Nov 27 2025

Strong low pressure over eastern Ontario will continue to exit
through Quebec today. Winds over the open lake have eased to high
end gales and they will persist through at least late afternoon. The
gale warning may be able to end slightly earlier than its current
end time tonight. Light westerly winds will set up across the Lake
Friday night and become southerly by Saturday morning.

For the nearshore areas of southeast WI, gale force gusts are
expected through at least midday, but confidence is lower for the
afternoon. A Small Craft Advisory will replace the Gale Warning when
the time comes.

Low pressure will track from eastern Kansas Saturday morning to the
southern tip of Lake Michigan Saturday night, and then reach Lake
Huron by mid Sunday while deepening slightly. Widespread, moderate
to heavy snow will overspread the south half of Lake Michigan.
Southeast winds Saturday will become easterly and then westerly as
the low crosses the Great Lakes region. Gales are not anticipated at
this time, although a period of gusty northwest winds is expected
Sunday.

Cronce

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Winter Storm Watch...WIZ056-WIZ057-WIZ058-WIZ059-WIZ060-WIZ062-
     WIZ063-WIZ064-WIZ065-WIZ066-WIZ067-WIZ068-WIZ069-WIZ070-
     WIZ071-WIZ072...midnight Saturday to 6 AM Sunday.

LM...Gale Warning...LMZ080-LMZ366-LMZ565-LMZ567-LMZ669-LMZ671-
     LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-
     LMZ876-LMZ878 until midnight Friday.

     Gale Warning...LMZ261-LMZ362-LMZ364-LMZ563 until 3 AM Friday.

     Gale Warning...LMZ643-LMZ644-LMZ645-LMZ646 until 6 PM Thursday.

&&

$$

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