250
FXUS63 KGRB 010641
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
141 AM CDT Sat Aug 1 2026

Forecast discussion for routine morning forecast issuance

.KEY MESSAGES...

- Widespread light rain with a few thunderstorms is expected
  through this morning. No severe weather is expected.

- There is an increased risk for rip currents along Lake Michigan
  beaches south of Sturgeon Bay tonight and Sunday.

- Quiet weather returns tonight through Monday.

- Scattered showers and thunderstorms return Tuesday and
  Wednesday as a cold front moves through the region.

&&

.DISCUSSION...
Issued at 141 AM CDT Sat Aug 1 2026

Widespread light rain will continue early this morning as a low
pressure system over northern Illinois tracks through the northern
Ohio Valley. This rain will end from west to east throughout the
morning as the low pulls away from the region. A few rumbles of
thunder cannot be ruled out, as GLM and lightning data indicate a
few flashes at various times. Additional showers and a few
thunderstorms will be possible this afternoon from daytime heating
as some modest instability builds across the region with a few
hundred J/kg of SBCAPE. Highs today will generally range from the
middle 70s to around 80 under cloud cover and persistent
northeast winds.

Surface high pressure will build into the Upper Great Lakes
tonight and remain dominant through Monday night. This will yield
clear to partly cloudy skies, light winds, and pleasant mid-
summer conditions. High temperatures will steadily warm from the
mid and upper 70s on Sunday to the upper 70s to lower 80s on
Monday under ample sunshine.

The next notable weather system arrives Tuesday into Wednesday as
an upper-level shortwave trough and associated surface cold front
push east across the Northern Plains into the Upper Midwest.
Moisture return ahead of the boundary will push dew points back
into the 60s, generating MUCAPE of 500-1000 J/kg and deep-layer
shear of 25-30 knots. This environment will bring scattered
showers and thunderstorms from Tuesday afternoon through
Wednesday morning. While severe weather risk remains low at this
time due to modest instability, parallel flow aloft relative to
the frontal boundary could result in localized training of shower
activity. Lighter precipitation chances linger into Thursday as
cooler, near-normal air settles back over the region with highs
returning to the upper 70s and lower 80s.

&&

.AVIATION...for 06Z TAF Issuance
Issued at 1109 PM CDT Fri Jul 31 2026

Periods of light to moderate rain are expected to continue across
the region through tonight, becoming mainly focused across east-
central WI by Saturday morning. The rain will exit the region to
the southeast by midday Saturday, but the MVFR cigs at the east-
central WI TAF sites will continue through Saturday afternoon.
VFR conditions are anticipated at the central and north-central
WI TAF sites through this TAF period. There are signs of isolated
showers and storms developing Saturday afternoon in far northeast
WI and moving southwest, but confidence is not high enough to
include a mention in the TAFs at this time.

There are also indications of patchy fog development in far
north-central WI early Saturday morning, which may cause reduced
IFR vsbys at the RHI TAF site for a period.

Light and variable winds will become north/northeasterly overnight
into Saturday. Gusts of 15 to 20 kts are possible at the east-
central WI TAF sites late tonight through Saturday morning, with
a few gusts to 15 kts at the central and north-central WI TAF
sites Saturday afternoon, becoming area-wide Saturday evening.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Beach Hazards Statement through Sunday evening for WIZ050.
&&

$$

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

NWS GRB Office Area Forecast Discussion