NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 210250
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
850 PM CST Thu Nov 20 2025

.KEY MESSAGES...

- Stratus clouds and some fog and drizzle continue through
  tonight.

- Temperatures several degrees above normal this weekend into
  early next week.

- 70-80 percent chance of rain Monday night lingering into
  Tuesday. Then polar air to gradually arrive by Thanksgiving
  Day.

&&

.UPDATE...
Issued 852 PM CST Thu Nov 20 2025

Forecast is largely on track this evening. 8 PM surface
observations place a weak cold front along an approximate
Rhinelander - Eau Claire - Twin Cities axis. The affiliated wind
shift across the boundary becomes progressively weaker with
southwest extent, which will translate to a gradual frontal
progression across southern Wisconsin tonight. Given slow
frontal progression, have thus nudged temperatures & dew points
up slightly through the overnight period. With the post-frontal
push of drier air lagging slightly behind the slow-moving cold
front, have also maintained mentions of fog and drizzle across
most locations through the predawn hours. Don't currently see
any robust signals for dense fog in model guidance, but will
nevertheless be monitoring trends through tonight. The front
should clear the area following daybreak Friday, resulting in
clearing skies during the second half of the morning hours.

Quigley

&&

.SHORT TERM...
Issued 259 PM CST Thu Nov 20 2025

Tonight through Saturday morning:

Swly winds and weak warm advection will likely maintain the
stratus clouds and some fog and drizzle this afternoon into
tonight. This is occurring well south of cyclogenesis from nrn
Ontario into Hudson Bay with its weak, trailing cold front to
gradually move across srn WI tnt. Fairly significant subsidence
and drying will then take hold toward Fri AM with PWATs dropping
to 0.20 inches. Thus expect to lose the stratus sometime during
the morning hours.

A separate shortwave trough in the srn USA jet stream will
then track from the central Great Plains across the Ohio Valley
for Fri-Sat. The QG dynamics and overall lift will remain to the
south, but broken to overcast high cloud cover could occur over
far srn WI on Fri. Otherwise a weak sfc ridge will prevail over
srn WI with mostly clear to partly cloudy skies north of the
high cloud cover into Sat AM. Temps will remain several degrees
above normal.

Gehring

&&

.LONG TERM...
Issued 259 PM CST Thu Nov 20 2025

Saturday afternoon through Thanksgiving Day:

For Saturday afternoon and Sunday a Canadian shortwave trough in
nwly flow aloft will track from the nrn Great Lakes to the lower
Great Lakes. At the surface, a trough/cold front will approach
Sat afternoon with swly winds and warm advection ensuing. A band
of cloud cover will occur with the QG lift but no precipitation
is expected at this time. The weak cold front will then pass
late Sat nt. High pressure will then follow for Sun afternoon
and night. Relatively mild temps will continue for the weekend.

Clouds will increase Monday with rain becoming widespread Mon nt
as a shortwave trough tracks from the central or srn high plains
toward IL and srn WI. This shortwave trough will shear out as it
approaches due to a more dominant upper wave approaching the
Upper MS River Valley in the nrn jet stream. Nevertheless, warm,
moist advection and PVA will bring rain to the region.
A sfc low associated with the dominant upper wave will then
track across nrn WI or just north of Lake Superior on Tue with
its polar cold front to arrive over srn WI Tue afternoon. The
cold advection will initially be gradual but increase into Wed
and Thanksgiving Day as the low moves into Quebec. Temps will
fall below normal by Thanksgiving Day.

Gehring

&&

.AVIATION...
Issued 852 PM CST Thu Nov 20 2025

Mostly MVFR flight categories prevail this evening as a cold
front slowly approaches the region from western Wisconsin.
Pockets of IFR CIGs and VIS readings remain over southeastern
and south-central Wisconsin. Will be accounting for latest obs
trends in the coming 03Z update. The aforementioned front will
gradually work through the area through daybreak Friday,
resulting in a weak northwest wind shift. Drier air will slowly
move into the region behind the frontal boundary, resulting in
the eventual return of VFR flight categories Friday morning.

Quigley

&&

.MARINE...
Issued 259 PM CST Thu Nov 20 2025

A weak cold front over the Upper Mississippi River Valley this
afternoon will slowly move across Lake Michigan tonight. Modest
southwest winds will shift northwesterly and continue through
Friday. Light to modest north winds Friday night will become light
and variable Saturday morning when high pressure moves across the
region. Winds will become southwesterly again Saturday afternoon
and evening, then westerly late Saturday night and Sunday with the
passage of another weak Canadian cold front.

Gehring

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...None.
&&

$$

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