NWS-Green Bay Forecast Discussion

						FXUS63 KGRB 031157
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
657 AM CDT Fri Jul 3 2026

Updated aviation portion for 12Z TAF issuance

.KEY MESSAGES...

- Isolated to scattered showers and thunderstorms are expected at
  times throughout today into this evening. A few storms may
  become strong and produce strong, gusty winds.

- Additional chances for showers and thunderstorms are expected
  throughout the holiday weekend.

&&

.DISCUSSION...
Issued at 308 AM CDT Fri Jul 3 2026

Precipitation/Thunder Chances...Radar and satellite imagery early
this morning showed dry conditions under mostly cloudy skies in
eastern and central WI, while some fog was developing in north-
central WI where clouds have cleared and winds are calm. Anticipate
the fog, dense at times, to continue in north-central WI through
this morning before burning off after sunrise. Meanwhile, the
boundary that has been the driver for precip over the past few days
was located across IA early this morning producing scattered showers
and thunderstorms. While this boundary is progged to stay mainly
south of the area today, its close proximity to the southern portion
of the forecast area will keep a very low chance (15-25%) of showers
and storms in central and east-central WI throughout the day.
Additionally, CAMs are indicating a lake breeze off of Lake Superior
will generate an isolated line of showers and storms along the
WI/Upper MI border during the afternoon and evening. Generally, the
storms throughout the day will be pulse-like storms, but a few may
produce strong, gusty winds.

After this evening, the forecast becomes muddled due to the
potential for the remnants of the lake breeze and any outflow
boundaries interacting with a mid-level shortwave and surface low
progged to move over the Upper Mississippi Valley/western Great
Lakes sometime between late Friday and Saturday. Another shortwave
looks to trail this system late Saturday into Sunday. Since CAMs and
global ensembles continue to disagree with the placement and timing
of the initial shortwave and surface low, forecast confidence is low
regarding when and where any showers and thunderstorms will occur
and their severity from tonight through Sunday. Main takeaway is,
showers and storms are anticipated at times throughout the holiday
weekend, but monitor the forecast as small scale features evolve.

A drier forecast looks to develop for the early part of next week
with upper-level ridging building over the western Great Lakes.
Global ensembles then indicate the next chance for showers and
storms occurring sometime midweek next week with the arrival of a
shortwave from the north.

Temperatures...Above normal temperatures are expected for today with
highs mainly in the mid 80s with dew points ranging from the mid 60s
to low 70s, highest in east-central WI. This will lead to heat
indices in the low 90s in east-central and far northeast WI.
Temperatures and dew points are progged to slightly decrease for
Saturday and then again on Sunday, but this may change depending on
what precip occurs. Temperatures warm into next week, but dew points
should remain at slightly more tolerable levels.

&&

.AVIATION...for 12Z TAF Issuance
Issued at 657 AM CDT Fri Jul 3 2026

VFR conditions prevailed across most of the region this morning
under high clouds, with the exception in north-central and
portions of central WI where LIFR or IFR conditions prevailed due
to patchy fog and a low stratus deck. Anticipate the low clouds
and fog to lift within the next 2-3 hours and return to VFR.
Outside of potential isolated showers and storms throughout the
day, VFR conditions are expected to prevail for the majority of
the time throughout this TAF period.

Much uncertainty revolves around the timing and placement of the
showers and storms throughout the day. Have only included PROB30
groups for showers at the east-central WI TAF sites for a couple
periods during the afternoon and evening. Showers may reach the
central WI TAF sites this morning as an area of rain, with some
embedded thunder, was lifting into west/southwest WI this morning.
However, there is a decent amount of dry air near the surface,
which may limit its progression. Have the greatest confidence for
storms reaching the RHI TAF site during the afternoon and evening,
but the exact timing is uncertain, so included thunder in a PROB30
group for now.

&&

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

&&

$$

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