127
FXUS63 KGRB 241730
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
1130 AM CST Mon Nov 24 2025

Updated aviation portion for 18Z TAF issuance

.KEY MESSAGES...

- Rain, low clouds and fog arrive later this afternoon and
  evening, and persist through Tuesday.

- Accumulating snow is likely over northern Wisconsin late Tuesday
  night into Thursday, with heavy snow expected in Vilas County.
  A Winter storm Watch has been issued for Vilas County.
  Additional winter weather headlines may be needed for Oneida,
  Forest and Florence counties.

- Strong northwest winds will gust to 25 to 40 mph Wednesday into
  Thursday. A Gale Watch has been posted for Lake Michigan,
  including the bay.

&&

.DISCUSSION...
Issued at 317 AM CST Mon Nov 24 2025

Mid-level clouds covered most of the forecast area early this
morning; the result of WAA developing ahead of an approaching
cold front. WV imagery showed an upper low moving from eastern CO
into western KS. Satellite and weather observations showed
extensive low clouds and fog lifting north through IA/IL.

The remnants of the Central Plains upper low will lift northeast
toward the Great Lakes late this afternoon and tonight, and this
will induce weak cyclogenesis along a cold frontal boundary as it
edges into WI. This system will draw mild and moist air into the
region, leading to widespread low clouds/fog and periods of light
to moderate rainfall through Tuesday.

Winter Storm: The resident low pressure system will deepen rapidly
as a strong upper low approaches from the Northern Plains Tuesday
night into Wednesday. This system will bring a mix of rain/snow
Tuesday night, which should change to mainly snow on Wednesday. As
the low shifts northeast Wednesday night into Thursday, gusty
northwest winds will bring potential for lake-effect snow to the
Lake Superior snowbelt, including Vilas County. Probabilistic
forecasts show a high likelihood of 1+ inches of snow along and
north of a line from Wausau to Wausaukee, with increasing amounts
as you head farther north. Most of this region will probably see
1-3 inches of snow, but much higher amounts are expected over
Vilas County, where there is now a 50-90 percent chance of 12+
inches in the northern part of the county. A Winter Storm Watch
has been issued for Vilas County late Tuesday night through
Wednesday night. Additional winter weather headlines (probably an
advisory) will eventually be needed for Oneida, Forest and
Florence counties, for a combination of 2 to 5 inches of snow and
wind. Holiday travelers and hunters heading to the Northwoods
during the late Tuesday night through Thanksgiving Day period
will likely have to contend with hazardous travel conditions,
especially in the Lake Superior snowbelt. Winds will also be a
concern with this system, as gusts over the land areas reach 30 to
40 mph Wednesday into Thursday. Winds this strong could produce
considerable blowing/drifting of newly fallen snow across the
Northwoods.

Any lingering lake-effect snow showers ahould taper in Vilas
County off Thursday night into Friday. An inverted surface trough
may bring a chance of snow or mixed snow/rain to the region over
the weekend.

Temperatures: Normal to above normal temperatures are expected
through Tuesday, with much below normal readings likely for the
rest of the week.

&&

.AVIATION...for 18Z TAF Issuance
Issued at 1130 AM CST Mon Nov 24 2025

Mix of MVFR/VFR conditions this afternoon as mid and high clouds
continue to push into the region as a low pressure system centered
over Kansas advects higher moisture levels into the region. Upstream
IFR clouds and vsbys are being observed across Iowa and SE
Minnesota. As the low continues to into the middle Mississippi Valley
the low clouds and light rain should lift into central WI late this
afternoon (after 23Z). IFR conditions will then spread over the rest
of the region this evening/overnight. Along with the low clouds the
combination of light rain and fog should results in periods of
MVFR/IFR vsbys overnight into Tuesday morning. AUW, CWA, and RHI
have the highest probabilities (20-30%) of see vsbys drop below
1SM. Areas south of a AUW to GRB line should see a brief break in
the rain Tuesday morning, however, rain will return during the
afternoon. Beyond the TAF period expect a transition to from rain to
snow late Tuesday night into Wednesday as much colder air dives into
the region. Along with the change over to snow northwest winds are
expected strengthen Wednesday with gusts reaching 35-45 mph.

&&

.MARINE...
Issued at 317 AM CST Mon Nov 24 2025

Probabilistic forecasts are now showing a 60-90 percent chance of
northwest gales on Lake Michigan Wednesday into Thursday. A Gale
Watch has been posted from 15z/Wed through 18z/Thu on both the
lake and bay.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Winter Storm Watch from late Tuesday night through late
Wednesday night for WIZ005.
&&

$$

DISCUSSION.....Kieckbusch
AVIATION.......GK
MARINE.........Kieckbusch

NWS GRB Office Area Forecast Discussion