192
FXUS63 KGRB 042254
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
554 PM CDT Thu Jun 4 2026

Updated aviation portion for 00Z TAF issuance

.KEY MESSAGES...

- An Air Quality Advisory is in effect for portions of northeast
  and east-central WI until 11 pm this evening.

- There is a 40-70% chance of showers and storms from late this
  afternoon into Friday morning.

- Additional storms are expected again Friday afternoon and
  evening. Some of the storms could become strong or severe with
  damaging winds and large hail. The highest risk of stronger
  storms will be from 4 pm to 10 pm.

- Increasing heat and humidity will result in the heat index
  climbing into the 90s at most places later next week.

&&

.DISCUSSION...
Issued at 151 PM CDT Thu Jun 4 2026

Another warm afternoon with temperatures in the lower to
middle 80s. The relative humidity dropped to 25 to 35% away from
the bay and lake. Meanwhile, scattered showers and thunderstorms
developed across western Wisconsin over the last hour or two.

The scattered showers and storms are expected to move into north-
central and central WI between 3 pm and 6 pm. Brief heavy rain,
gusty winds and small hail are possible with the stronger storms.
The showers and storms are then expected to spread eastward into
northeast and east-central WI around or shortly after midnight.
There is still a lot of uncertainty in the extent of the
precipitation later tonight into Friday morning across east-
central WI due to differing model solutions. On Friday, a weak
cold front will move across the area bringing another round
of showers and thunderstorms Friday afternoon and evening.
Bufkit soundings indicated 800-1,200 of CAPE and 0-6 km
shear values of 30-35 knots to support the potential for
stronger/severe storms. It all may come down to how
much clearing takes places Friday morning into the afternoon.

Otherwise, there is a small chance of isolated storms across
east-central WI Saturday afternoon. The next widespread chance
of showers and storms will be Monday afternoon into Tuesday.
Stronger storms will be possible during this time frame.

Later next week, heat and humidity will build across the region
with temperatures well above normal for early June. By late in
the week, many locations will experience heat index values into
the 90s, and possibly a few locations hitting the triple digits.
The intense heat could cause a few roads/highways to buckle.

&&

.AVIATION...for 00Z TAF Issuance
Issued at 554 PM CDT Thu Jun 4 2026

Band of showers with embedded thunderstorms has developed along a
frontal boundary extending from north-central WI back toward central
IA late this afternoon. This boundary will shift east this evening
and as showers move over any terminals expect brief periods of
MVFR/IFR conditions. Have the best timing for lightning framed out
in TEMPO groups, for AUW, CWA, and RHI the best chance will be 00-
03Z with decreasing chances overnight. For ATW, GRB, and MTW the
chance for storms comes overnight mainly 07-11Z. It is also less
certain that lightning will even persist into east-central WI as
instability is forecast to be minimal in that region overnight.

As the showers dry up in central and northern WI overnight period
of IFR status and patch fog is possible. Have cigs dropping to 600-
700ft for the pre-dawn hours at AUW, CWA, and RHI. Conditions should
gradually improve Friday morning as cigs rise.

Another round of thunderstorms is likely (60-70%) Friday afternoon
and evening as a cold front drops south across the region. Have
framed out forecast arrival window for those thunderstorms will
PROB30 groups at all TAF sites.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Beach Hazards Statement until 1 AM CDT Friday for WIZ022-040-050.
&&

$$

DISCUSSION.....Eckberg
AVIATION.......GK

NWS GRB Office Area Forecast Discussion