956
FXUS63 KGRB 260619
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
119 AM CDT Sat Sep 26 2026

Forecast discussion for routine morning forecast issuance

.KEY MESSAGES...

- Patchy fog development will be possible north and west of the
  Fox Valley early this morning.

- High pressure will maintain mostly dry weather through early
  next week.

- Next widespread rain chances arrive during the middle of next
  week.

&&

.DISCUSSION...
Issued at 119 AM CDT Sat Sep 26 2026

Mostly clear skies and light winds have led to patchy fog across
the region early this morning. At the moment the fog appears to be
light and patchy, as evidenced by the METAR observations that go
on a roller coaster for their visibilities. However, there is
still the potential for a bank of more persistent dense fog to
develop per some of the hi resolution models. Will handle any fog
with subsequent SPS products if necessary.

Rain chances over the weekend continue to look rather pessimistic
as high pressure wins the battle, as it so often does in this
scenario. Models continue to show light rain splitting off to our
north and south as low pressure ejects into northern Canada,
leaving PoPs at a meager 15 to 20%. While a sprinkle or two
wouldn`t be out of the question over central or north-central
Wisconsin, expect most of the forecast area to remain dry.

Starting to see similar decreasing trend with rain chances during
the middle of next week as abundant low-level dry air remains in
place beneath Hudson Bay high. Chances for widespread rainfall
still look on track as PWATs approach 90th percentile, though
ensembles begin to flatten out the upper trough as it approaches
the Midwest and encounters sturdy omega ridge. Probabilities for
one inch of rainfall are steady from the previous run, around 20
to 30%, although much lower than they were a day or two ago.
Additionally, better moisture return and forcing look to remain
off to our south, which would mean more of a glancing blow to our
southern tier of counties. All in all, signs still point toward a
decent stratiform rain setup, though excessive rainfall potential
remains in question due to prolonged duration and current drought
status. Worth mentioning is that predictability remains fairly low
this far out in the forecast period, so there is still time for
things to change.

Things get interesting late next week as high pressure builds in
from southern Canada while a low pressure system over the
southern Plains approaches from the southwest. There is some
question how far north this low will get, which will impact POPs
late next week. However, given the recent trends for the high to
win out would nudge towards the drier solution at this point in
the forecast.

&&

.AVIATION...for 06Z TAF Issuance
Issued at 1101 PM CDT Fri Sep 25 2026

VFR conditions are expected through this TAF period with high
clouds moving over the area late tonight into Saturday. Patchy fog
has developed for some in far north-central and northeast WI late
this evening. Anticipate this patchy fog will reach the east-
central WI TAF sites, and RHI later tonight into Saturday
morning, producing MVFR/IFR vsbys. Any fog will burn off by 12-13z
Sat. A few low to mid-level clouds will also be possible Saturday
afternoon.

Light and variable winds are expected tonight. Southeast winds
increase mid-morning Saturday to 5-10 kts, with a few gusts to 15
kts in central and north-central WI Saturday afternoon.

&&

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

&&

$$

DISCUSSION.....Kurimski
AVIATION.......Kruk

NWS GRB Office Area Forecast Discussion