264
FXUS63 KGRB 111218
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
718 AM CDT Sat Oct 11 2025

Updated aviation portion for 12Z TAF issuance

.KEY MESSAGES...

- Above normal temperatures into early next week, slightly cooler
  mid-week before warmer readings return late next week.

- A few showers/sprinkles possible near Lake Michigan today, but
  otherwise dry this weekend. Chance for light rain Sunday night
  into Monday and again late next week.

&&

.DISCUSSION...
Issued at 323 AM CDT Sat Oct 11 2025

Today into Sunday:

Temps were a little slow to fall across parts of central WI
overnight, but many spots have or should drop into the mid-upper
30s in the pre-dawn hours, so will not make any changes to the
Frost Advisory. Patchy ground fog is also possible across parts of
central and north-central WI through shortly after sunrise.

Dry conditions are expected for most of the weekend as mid and
upper level ridging move across the Great Lakes. The exception
will be near Lake Michigan, where delta Ts in the low teens
combined with moist/cyclonic flow behind a departing low pressure
system will bring some shower/sprinkles chances. Activity should
be pretty isolated and light (only a hundredth or two possible),
so will keep PoPs in the 10-24% range. Clouds will increase over
eastern WI this morning as well due to the north/northeast flow,
but look for more sunshine as you move west. As flow turns
southeast and temps aloft climb, look for any lake effect
showers to diminish late today, but moist/upslope flow will lead
to additional clouds over land, especially across central and
northern WI. Some fog will also be possible.

Highs this weekend will be above normal, mainly in the 60s, with a
couple spots possibly hitting 70 on Sunday in/west of the Fox
Valley. Lows tonight will be warmer than previous nights, with
most spots in the 40s to around 50. A few upper 30s will be
possible in the typical cold spots of central and north-central WI.

Sunday Night into Next Week:

Next chance for area-wide rain will arrive west to east after dark
Sunday into Monday morning as a frontal boundary moves across the
region. LREF showing highest probabilities over north-central WI,
so will carry likely (60-70%) PoPs there, with 25-50% PoPs
elsewhere. As with the last front, the precip looks to be on the
light side, with LREF showing only a 30% chance of more than a
quarter of an inch of rain over north-central WI, with lower
chances to the south. Very low threat of a rumble of thunder as
little to no instability will accompany the front (only up to
~200 MUCAPE), so will not carry any thunder. Mainly dry conditions
are expected Tuesday into Wednesday, and possibly into Thursday
or Friday, as upper ridging builds into the western Great Lakes.
However, models vary on the timing/strength of the ridge, which
will determine just how long we can hold off the next chance for
rain. It does appear that rain (storm?) chances increase towards/
into next weekend as a deep trough approaches from the west. Temps
will remain above normal into Monday, especially across eastern
WI where we could touch 70 degrees. Then a return to near normal
temps is forecast mid-week with a gradual warming trend towards
next weekend.

&&

.AVIATION...for 12Z TAF Issuance
Issued at 718 AM CDT Sat Oct 11 2025

Patchy ground fog across north-central WI will lift early this
morning. Otherwise, look for an area of MVFR clouds to slowly
shift west/south across parts of northeast WI. The cloud deck
should stay east of AUW/CWA, but may get to RHI for a time. This
cloud deck will scatter out/retreat this afternoon, but increase
again later this evening and overnight.

Light winds will become east and southeast through the day,
remaining under 10 kts.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Frost Advisory until 8 AM CDT this morning for WIZ030-035-036-
045.
&&

$$

DISCUSSION.....Bersch
AVIATION.......Bersch