Area Forecast Discussion
Issued by NWS Green Bay, WI

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528
FXUS63 KGRB 121149
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
649 AM CDT Sun Oct 12 2025

Updated aviation portion for 12Z TAF issuance

.KEY MESSAGES...

- Above average temperatures continue early this week, slighter
  cooler mid-week.

- Light rain returns for most tonight into Monday morning, with a
  few chances for additional rain next week.

&&

.DISCUSSION...
Issued at 352 AM CDT Sun Oct 12 2025

Fog/Low Stratus/Cloud Trends: Southeast, upslope, moist flow will
continue to produce a large north to south orientated area of low
stratus over much of the area. This area should remain pretty
stationary this morning, morphing a little on the sides, then
should start to erode through the later morning and afternoon
hours. Some disagreement on just how fast the lower clouds will
depart. On either side of the stratus deck, mostly clear skies
and light winds could lead to some patchy ground fog early this
morning. Any fog would burn off shortly after sunrise. Otherwise,
look for high clouds to spread across the region for most of the
day.

Rain Chances: Dry conditions are expected for most of today as
mid-upper level ridging exits to the east. Chance for rain showers
arrive west to east after dark into early Monday morning as a
weakening frontal boundary moves across the region. Highest
probabilities reside across central and north-central WI, where we
will continue the likely (55-70%) PoPs, with 20-50% PoPs
elsewhere. As with the last front, the precip looks to be on the
light side due to limited moisture and dynamics, with only a
20-30% chance of more than 0.15" of rain over central and north-
central WI, with lower chances to the south. Thunder threat is
pretty much nil with no instability to work with (only up to ~150
MUCAPE). The showers will exit west to east Monday morning. As an
omega block sets up over the CONUS mid-week, mainly dry conditions
are expected, but a weak shortwave could clip the south on
Tuesday, bringing small (15-25%) chance for showers. Ridging
builds over the western Great Lakes in the mid-late week period,
but a couple ridge riders could touch off some shower activity.
But the better rain threat looks to arrive over the weekend as a
deep trough approaches from the west.

Temperatures: Highs today look to be a little above normal for
most locations, with most spots climbing into the low to mid 60s.
If/where the lower clouds stick around into the afternoon, temps
will struggle to climb out of the upper 50s or low 60s. A much
milder night compared to the past several nights in on tap as
persistent WAA occurs ahead of the approaching front. Lows should
hold in the upper 40s and 50s. On Monday, the showers/clouds will
limit temps from rising much in the morning, but as the
clouds/showers exit and the CAA is slow to arrive, the W/NW
downsloping winds and sunshine will allow temps to quickly climb
into the mid 60s to around 70 for most locations (a little cooler
near Vilas Co.). The stronger CAA arrives on Tuesday into
Wednesday, dropping highs back near seasonal normals, with highs
in the upper 50s to low 60s. A gradual warming trend toward
slightly above normal temps is expected late in the week.

&&

.AVIATION...for 12Z TAF Issuance
Issued at 648 AM CDT Sun Oct 12 2025

A large north-south orientated area of MVFR stratus, along with
other low clouds to its west, will continue to move across the
area this morning. The low clouds will eventually erode, but
models differ on just how fast this will occur. Followed the GLAMP
guidance for the most part, but trends will need to be monitored.
Otherwise, look for high clouds spread across the region through
the day. Dry conditions are expected for the daylight hours, then
light showers will spread west to east into the region ahead of a
weak cold front, especially across central and north-central WI.
Some lower clouds will be along and behind this front.

Southeast winds will increase through the morning, gusting to
around 20 kts this afternoon. LLWS is expected this evening into
early Monday as surface winds decrease and south winds at 2000 ft
increase to 35-45 kts.

&&

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

&&

$$

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