946
FXUS63 KGRB 181748
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
1148 AM CST Tue Nov 18 2025

New Information added to update section

.UPDATE...
Issued at 1148 AM CST Tue Nov 18 2025

Added Outagamie, Winnebago, Calumet, and Manitowoc counties into
the Winter Weather Advisory and extended the Advisory until 3 pm.
Decent snowfall rates continue within the snow band and across
parts of central and east-central WI. Webcams around Oshkosh are
showing slushy accumulations occurring on roads and within the
heavier snowfall rates. This area of heavier precip rates will
continue east and impact much of east-central Wisconsin over the
next 1-3 hours. Additional accumulations of 1-2 inches appears
possible, highest on grassy surfaces.

Motorists should plan for stretches of winter driving if venturing
out at Appleton, Oshkosh, Chilton, and Manitowoc over the next few
hours.

UPDATE
Issued at 944 AM CST Tue Nov 18 2025

No changes to the Winter Weather Advisory in effect for central
Wisconsin until noon today. Frontogenetical snow band continues
over northern Wood to Waupaca counties this morning, locally
dropping visibilities below one mile at times. Marshfield`s
visibility dropped to 1/2 mile briefly. Area webcams show that
some snow is accumulating on roads from Marshfield to Stevens
Point in the more intense snow band. Even though impacts have
been minor so far this morning, will continue with the Advisory
given locally higher snowfall rates and some accumulations ongoing
on the roads.

&&

.KEY MESSAGES...

- Light to moderate snow in central Wisconsin today, with
  accumulations of 1 to 3 inches expected west of the Fox Valley.
  A Winter Weather Advisory is in effect for Wood, Portage,
  Waupaca and Waushara counties until noon.

- Less than an inch of snow expected from the Fox Valley to
  Manitowoc County.

- Seasonal temperatures with below normal precipitation for the
  rest of the week.

&&

.DISCUSSION...
Issued at 346 AM CST Tue Nov 18 2025

No changes to the ongoing winter weather headlines.

A frontogenetic band of precipitation was just moving into the
far southwest part of the forecast area at issuance time. The
regional radar mosaic showed that the northward push of the band
had just about ended to our west, suggesting that it will set up a
little farther south than was previously expected. Most of the
meso-models have caught on to this, and don`t expand the
precipitation farther north than our southern two rows of
counties. Though most observations to our south have shown rain
early this morning, colder surface wet bulb temperatures in
central and east central WI should result in a fairly quick
changeover to snow. Have adjusted pops/QPF/snowfall accordingly,
which focuses most of the accumulation over southern Wood,
southwest Portage and Waushara counties (roughly the south half of
the advisory area). Considered whether or not the advisory needed
to be expanded east into Winnebago County, but decided against
it. Boundary layer temperatures/wet bulbs were warmer near Lake
Winnebago early this morning, and east winds during the day will
likely keep them milder, which should limit accumulation to an
inch or less. As such, there have been no changes to the Winter
Weather Advisory. An upper low will track through Illinois this
afternoon, and the deformation zone of this feature will continue
to produce light snow or mixed rain/snow over C/EC WI until mid to
late afternoon.

Rest of the forecast: Zonal flow aloft will bring a couple quick-
moving and moisture deficient systems through the region Wednesday
night into Thursday and Saturday into Saturday night. Precipitation
chances are fairly low, and mainly focused over northern WI.
Seasonable temperatures are also anticipated.

&&

.AVIATION...for 18Z TAF Issuance
Issued at 1113 AM CST Tue Nov 18 2025

The main focus of this forecast centers on ongoing wintry
precipitation across east-central Wisconsin this afternoon,
followed by the potential for fog late tonight.

A band of rain and snow is impacting the east-central Wisconsin
terminals (GRB/ATW/MTW), producing MVFR ceilings and visibilities.
Brief periods of IFR conditions are possible with the heavier
precipitation bands, particularly where precipitation remains all
snow. This activity is expected to exit the region to the east
between 22Z and 24Z.

High pressure will build into the region for tonight. Clearing
skies and light winds, combined with boundary layer modification
from today`s precipitation, will create favorable conditions for
fog development. Confidence is increasing for IFR to LIFR
visibilities developing at AUW, CWA, GRB, and ATW generally
between 07Z and 15Z Wednesday morning. Lower confidence at RHI due
to drier air at the surface, though patchy fog cannot be ruled
out.

Any fog is expected to burn off by mid-morning (14-15Z), leaving
VFR conditions with scattered mid and high clouds for the rest of
the taf period. Looking ahead, MVFR ceilings are expected to
return to the area late on Wednesday afternoon and Wednesday
night.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 3 PM CST this afternoon for
WIZ035>037-045.

Winter Weather Advisory until 3 PM CST this afternoon for WIZ038-
048>050.
&&

$$

UPDATE.........MPC
DISCUSSION.....Kieckbusch
AVIATION.......MPC