488
FXUS63 KGRB 162250
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
550 PM CDT Thu Oct 16 2025

Updated aviation portion for 00Z TAF issuance

.KEY MESSAGES...

- Temperatures will trend warmer late this week, with highs in the
  middle 60s to middle 70s Friday into Saturday.

- Periodic rain and a few thunderstorms expected this evening
  through Sunday. Heavy rainfall is possible in the Fox Valley and
  lakeshore areas late Saturday night into Sunday morning, with a
  15 to 25 percent chance of amounts greater than 1 inch.

- Windy periods also expected late this week, with south winds
  gusting to 25 to 30 mph on Friday, and northwest winds gusting
  to 25 to 35 mph on Sunday.

&&

.DISCUSSION...
Issued at 242 PM CDT Thu Oct 16 2025

An area of light rain is approaching central Wisconsin early this
afternoon as WAA and a LLJ work into the region. With relatively weak
forcing CAMs tend to diminish the shower activity as it moves
further west this afternoon, however, with ample moisture in place
(PWATS up to 1.5") keep chance (30-40%) PoPs going through the
evening. Another round of showers is possible tonight as a warm
front, currently stalled across central WI, lifts northward across
Wisconsin. The 850mb LLJ is also expected to strengthen to to around
40-45kts with a nose generally along the WI/UP border which is where
the greatest precip chances are overnight. A few rumbles of thunder
also remain possible, however, with minimal instability expect
thunderstorm activity to be minimal. A brief period of ridging
should bring an end to the precip Friday morning.

After a brief dry period the chance (40-70%) for showers and
isolated thunderstorms arrives Friday afternoon/evening as a cold
front swings across the region. Ahead of the front breezy southerly
winds will bring well above normal temperatures into the region with
highs getting into the upper 60s to middle 70s at most locations.
Scattered showers associated with the front are progged to continue
into Saturday morning, however, recent ensemble guidance has been
more progressive with the front pushing east of the region Saturday
which may lead to much of Saturday trending dry, especially west and
north of the Fox Valley.

A potential more impactful system is forecast to arrive late
Saturday night into Sunday as an upper negatively tilted trough digs
into the western Great Lakes inducing an area of cyclogenesis over
lower Michigan. NBM probs to greater than 1" of rain have come down
for Sunday, however, 15-25% probs are still present in the Fox
Valley and lakeshore areas. Those area also have 30-40% probs for
greater than 0.5 inches of rain. Along with the rain strong
northwest winds are expected Sunday within the CAA regime. LREF
probs show 40-60% chances for greater than 30mph gusts Sunday
afternoon.

Uncertainty increases into the start of next week, but ensemble
trends favor a dry period Monday as another brief ridge builds over
the region. By Tuesday the next disturbance is forecast to arrive
return precip chances. Temperatures through next week are expected
to be near normal for late October.

&&

.AVIATION...for 00Z TAF Issuance
Issued at 549 PM CDT Thu Oct 16 2025

Scattered showers and MVFR CIGs are expected to work their way
east this evening from central Wisconsin to east-central Wisconsin
and the lakeshore as a warm front lifts through the area. Showers
will continue into the early overnight hours according to the CAMs
models with dry weather expected from west to east overnight
through Friday morning. A cold front will bring another chance for
showers Friday afternoon and evening as it tracks through the
region.

A strengthening low-level jet tonight will create a period of
LLWS overnight, mainly across central and northern WI. Southerly
surface winds are also expected to become breezy with gusts
reaching 15-20kts later tonight into Friday.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION.....GK
AVIATION.......Kurimski