NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 171742
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1142 AM CST Mon Nov 17 2025

.KEY MESSAGES...

- Band of rain/snow mix, changing to snow in many locations,
  Monday night and early Tuesday. Light accumulations possible.

- Additional precipitation chances for the latter portion of the
  workweek. Rain is favored at this time.

- Temperatures generally around average through the week.

&&

.UPDATE...
Issued 1123 AM CST Mon Nov 17 2025

A few sprinkles may occur late this morning into the afternoon
over southwest Wisconsin. Otherwise, forecast details for today
remain on track.

CMiller

&&

.SHORT TERM...
Issued 337 AM CST Mon Nov 17 2025

Today through Tuesday:

Dry conditions will continue early this morning through this
afternoon as high pressure moves southeast across the state. As the
axis of high pressure moves through the state this morning winds
will shift from northwest to southeasterly. Cloud cover will
increase across the region from the southwest to the northeast as
the high moves east and low pressure from the Rockies moves east.
High temps will climb into the mid 40s under the mostly to partly
clear skies and light southeasterly winds.

By this evening, mid level WAA and frontogenesis will move in across
the region. These mid level features will be driving the arc of
precipitation to the north of the sfc low. The 850 to 500 mb
frontogenesis will be transient but robust as it pushes through
southern Wisconsin. The WAA will create a broad area of rain and
wintry mix while the Fgen will create a narrow band of more intense
precip. Fgen will be at its strongest Monday night into early
Tuesday morning. There is some uncertainty in the exact location of
this band of high precip rates, but the best chances will be across
the northwest corner of our CWA which includes Sauk, Columbia,
Marquette, and Green Lake Counties.

Now for the other question of the day is wintry mix of rain and
snow. Initially precip will start out as light rain to light
rain/snow and move in from the southwest to the northeast.
Soundings are isothermal at zero degrees celsius for much of the
forecast area. Far southern Wisconsin favors temps wobbling just
above zero more often which will make rain more likely while areas
across the north of our forecast area will favor being just below
zero giving snow. This isothermal layer is roughly from 10kft to the
sfc. The narrow band of increased forcing (Fgen band) will result in
a more solid transition to snow. Snow will be very wet and heavy
under this band. The best timing for snow will be roughly from
Midnight to 5 AM. WAA will then start to win out and push the
rain/snow line north as we head into Tuesday morning. Could see a
few pockets of rain/snow mix persist, but these will be scattered.
Light rain will become the primary precip type as the morning goes
on with precip lingering into Tuesday afternoon.

Given all of this, wet heavy snowfall accumulations will be most
likely on grassy and/or elevated sfcs. Areas under the narrow Fgen
band could see some slushy accumulations on roadways, but this is
less likely than grassy areas. Most areas will see 0 to 1 inch of
snow while areas under Fgen band could see up to 2 inches. Now this
band will be transient so confidence is very low on seeing any
accumulations to 2 inches, but if the band stalls or slow down these
chances will increase. Any accumulations will quickly melt as
temperatures rise Tuesday morning. So impacts will be minor with
those at greatest risk being in our northwestern counties during the
start of Tuesday morning rush.

High pressure will move in Tuesday late afternoon/evening bringing a
return to dry conditions. Cloudy skies are likely to linger into
Tuesday night. Overnight lows will fall into the upper 20s to mid
30s.

Patterson

&&

.LONG TERM...
Issued 337 AM CST Mon Nov 17 2025

Tuesday night through Sunday:

The shortwave trough continues to push east overnight Tuesday
allowing for surface high pressure to move over WI. This will bring
colder temps with overnight lows in the mid 20s to lower 30s and
drier conditions to southern WI into Wednesday. High pressure will
works its way east through day and see more southerly winds and WAA
build into the area through Thursday. Will see gradually warmer
temps in the 40s and 50s midweek. Then another upper-level trough is
progged to dig across central Canada later Thursday. The associated
surface low will trek across Hudson Bay region and drag a weak cold
front across the Upper Midwest later Thursday into Friday. Meanwhile
long range models hint at another mid-level shortwave trough making
its ways across the Plains and into the Ohio River Valley for the
end of the week. While the NBM is showing a bit more activity with
the passage of these end of the week systems, the latest 00z
deterministic models are trending drier as they keep these systems
more separate with drier air in between the two troughs. So will
continue to monitor how chances trend over the next couple of days.

Wagner

&&

.AVIATION...
Issued 1123 AM CST Mon Nov 17 2025

VFR conditions are expected through today with some potential
for sprinkles in southwest Wisconsin. Winds will be light and
variable.

Tonight, Rain is expected with snow to a rain/snow mix over
central WI. A slushy inch may occur along a line from KDLL over
to KFLD, where areas elsewhere may only see a dusting, or only
accumulations on grassy surfaces.

CMiller

&&

.MARINE...
Issued 337 AM CST Mon Nov 17 2025

Light northwest wings will continue through today as high
pressure around 30.1 inch moves through the Upper Midwest. As the
high exits, low pressure around 29.8 inches progresses from the
central Plains through Illinois Monday night through Tuesday.
Southeast to east winds will develop across the lake as the low
moves in. The strongest winds are expected over the southern half
of the open waters. Light and variable winds are then expected
midweek as high pressure builds back into the Great Lakes region.

Patterson

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Small Craft Advisory...LMZ643-LMZ644-LMZ645-LMZ646...6 AM
     Tuesday to 9 PM Tuesday.

&&

$$

Visit us at weather.gov/milwaukee

Follow us on Facebook, X, and YouTube at:
www.facebook.com/NWSMilwaukee
www.x.com/NWSMilwaukee
www.youtube.com/NWSMilwaukee